diff --git a/libaegisub/common/color.cpp b/libaegisub/common/color.cpp
index e46a6cbdf1..d6484db97b 100644
--- a/libaegisub/common/color.cpp
+++ b/libaegisub/common/color.cpp
@@ -47,7 +47,10 @@ std::string Color::GetHexFormatted(bool rgba) const {
 }
 
 std::string Color::GetRgbFormatted() const {
-	return agi::format("rgb(%d, %d, %d)", r, g, b);
+	if (a)
+		return agi::format("rgba(%d, %d, %d, %d)", r, g, b, a);
+	else
+		return agi::format("rgb(%d, %d, %d)", r, g, b);
 }
 
 }
diff --git a/libaegisub/common/option.cpp b/libaegisub/common/option.cpp
index c75aad91f3..ad2fd897dc 100644
--- a/libaegisub/common/option.cpp
+++ b/libaegisub/common/option.cpp
@@ -113,6 +113,7 @@ class ConfigVisitor final : public json::ConstVisitor {
 		if ((size == 4 && string[0] == '#') ||
 			(size == 7 && string[0] == '#') ||
 			(size >= 10 && string.starts_with("rgb(")) ||
+			(size >= 13 && string.starts_with("rgba(")) ||
 			((size == 9 || size == 10) && string.starts_with("&H")))
 		{
 			values.push_back(std::make_unique<OptionValueColor>(name, agi::Color(string)));
diff --git a/libaegisub/common/parser.cpp b/libaegisub/common/parser.cpp
index 9301c1510c..ad81d346e5 100644
--- a/libaegisub/common/parser.cpp
+++ b/libaegisub/common/parser.cpp
@@ -88,6 +88,7 @@ struct color_grammar : qi::grammar<Iterator, agi::Color()> {
 
 		css_color
 			= "rgb(" >> blank >> rgb_component >> comma >> rgb_component >> comma >> rgb_component >> blank >> ')'
+			| "rgba(" >> blank >> rgb_component >> comma >> rgb_component >> comma >> rgb_component >> comma >> rgb_component >> blank >> ')'
 			| '#' >> hex_byte >> hex_byte >> hex_byte
 			| '#' >> hex_char >> hex_char >> hex_char
 			;
diff --git a/src/audio_display.cpp b/src/audio_display.cpp
index 0011a846a8..944cfcee28 100644
--- a/src/audio_display.cpp
+++ b/src/audio_display.cpp
@@ -898,8 +898,17 @@ void AudioDisplay::PaintMarkers(wxDC &dc, TimeRange updtime)
 	{
 		int marker_x = RelativeXFromTime(marker->GetPosition());
 
-		dc.SetPen(marker->GetStyle());
-		dc.DrawLine(marker_x, audio_top, marker_x, audio_top+audio_height);
+		if (marker->GetWidth() == 0) {
+			dc.SetPen(marker->GetStyle());
+			dc.DrawLine(marker_x, audio_top, marker_x, audio_top+audio_height);
+		} else {
+			int w = RelativeXFromTime((marker->GetPosition() + marker->GetWidth() - 1) + (ms_per_pixel - 1)) - marker_x - 1;	// Add (ms_per_pixel - 1) to get "rounding up" behavior
+
+			dc.SetBrush(wxBrush(marker->GetStyle().GetColour()));
+			dc.SetPen(*wxTRANSPARENT_PEN);
+
+			dc.DrawRectangle(marker_x, audio_top, w, audio_height);
+		}
 
 		if (marker->GetFeet() == AudioMarker::Feet_None) continue;
 
diff --git a/src/audio_marker.cpp b/src/audio_marker.cpp
index fe584891b8..0230562643 100644
--- a/src/audio_marker.cpp
+++ b/src/audio_marker.cpp
@@ -82,6 +82,36 @@ void AudioMarkerProviderKeyframes::GetMarkers(TimeRange const& range, AudioMarke
 		out.push_back(&*a);
 }
 
+class VideoPositionSnapPoint final : public AudioMarker {
+	int position = -1;
+
+public:
+	void SetPosition(int new_pos) { position = new_pos; }
+
+	int GetPosition() const override { return position; }
+	FeetStyle GetFeet() const override { return Feet_None; }
+	wxPen GetStyle() const override { return wxPen{}; }
+};
+
+class VideoPositionRange final : public AudioMarker {
+	Pen style;
+	int position = -1;
+	int width = 0;
+
+public:
+	VideoPositionRange(bool previous) : style{previous ? "Colour/Audio Display/Previous Frame Range" : "Colour/Audio Display/Current Frame Range"} { }
+
+	void SetPosition(int frame, int nextframe) {
+		position = frame + 1;
+		width = nextframe - frame - 1;
+	}
+
+	int GetPosition() const override { return position; }
+	int GetWidth() const override { return width; }
+	FeetStyle GetFeet() const override { return Feet_None; }
+	wxPen GetStyle() const override { return style; }
+};
+
 class VideoPositionMarker final : public AudioMarker {
 	Pen style{"Colour/Audio Display/Play Cursor"};
 	int position = -1;
@@ -92,7 +122,6 @@ class VideoPositionMarker final : public AudioMarker {
 	int GetPosition() const override { return position; }
 	FeetStyle GetFeet() const override { return Feet_None; }
 	wxPen GetStyle() const override { return style; }
-	operator int() const { return position; }
 };
 
 VideoPositionMarkerProvider::VideoPositionMarkerProvider(agi::Context *c)
@@ -105,8 +134,16 @@ VideoPositionMarkerProvider::VideoPositionMarkerProvider(agi::Context *c)
 
 VideoPositionMarkerProvider::~VideoPositionMarkerProvider() { }
 
-void VideoPositionMarkerProvider::Update(int frame_number) {
+void VideoPositionMarkerProvider::SetPositions(int frame_number) {
 	marker->SetPosition(vc->TimeAtFrame(frame_number));
+	range1->SetPosition(vc->TimeAtFrame(frame_number - 1), vc->TimeAtFrame(frame_number));
+	range2->SetPosition(vc->TimeAtFrame(frame_number), vc->TimeAtFrame(frame_number + 1));
+	snap1->SetPosition(vc->TimeAtFrame(frame_number, agi::vfr::START));
+	snap2->SetPosition(vc->TimeAtFrame(frame_number, agi::vfr::END));
+}
+
+void VideoPositionMarkerProvider::Update(int frame_number) {
+	SetPositions(frame_number);
 	AnnounceMarkerMoved();
 }
 
@@ -114,17 +151,35 @@ void VideoPositionMarkerProvider::OptChanged(agi::OptionValue const& opt) {
 	if (opt.GetBool()) {
 		video_seek_slot.Unblock();
 		marker = std::make_unique<VideoPositionMarker>();
-		marker->SetPosition(vc->GetFrameN());
+		range1 = std::make_unique<VideoPositionRange>(true);
+		range2 = std::make_unique<VideoPositionRange>(false);
+		snap1 = std::make_unique<VideoPositionSnapPoint>();
+		snap2 = std::make_unique<VideoPositionSnapPoint>();
+		SetPositions(vc->GetFrameN());
 	}
 	else {
 		video_seek_slot.Block();
 		marker.reset();
+		range1.reset();
+		range2.reset();
+		snap1.reset();
+		snap2.reset();
 	}
 }
 
-void VideoPositionMarkerProvider::GetMarkers(const TimeRange &range, AudioMarkerVector &out) const {
-	if (marker && range.contains(*marker))
+void VideoPositionMarkerProvider::GetMarkers(const TimeRange &timerange, AudioMarkerVector &out) const {
+	if (marker && timerange.contains(marker->GetPosition()))
 		out.push_back(marker.get());
+
+	for (auto range : {range1.get(), range2.get()})
+		if (range && timerange.overlaps({range->GetPosition(), range->GetPosition() + range->GetWidth() - 1}))
+			out.push_back(range);
+}
+
+void VideoPositionMarkerProvider::GetSnapMarkers(const TimeRange &timerange, AudioMarkerVector &out) const {
+	for (auto snap : {snap1.get(), snap2.get()})
+		if (snap && timerange.contains(snap->GetPosition()))
+			out.push_back(snap);
 }
 
 SecondsMarkerProvider::SecondsMarkerProvider()
diff --git a/src/audio_marker.h b/src/audio_marker.h
index ba725ed4cd..7316421462 100644
--- a/src/audio_marker.h
+++ b/src/audio_marker.h
@@ -29,6 +29,8 @@ class Pen;
 class Project;
 class VideoController;
 class VideoPositionMarker;
+class VideoPositionRange;
+class VideoPositionSnapPoint;
 class wxPen;
 
 namespace agi {
@@ -54,6 +56,10 @@ class AudioMarker {
 	/// @return The marker's position in milliseconds
 	virtual int GetPosition() const = 0;
 
+	/// @brief Get the marker's width
+	/// @return The marker's width if the marker should be a rectangle, or 0 if the marker should be drawn as a line (with the thickness specified by the style)
+	virtual int GetWidth() const { return 0; }
+
 	/// @brief Get the marker's drawing style
 	/// @return A pen object describing the marker's drawing style
 	virtual wxPen GetStyle() const = 0;
@@ -73,9 +79,12 @@ class AudioMarkerProvider {
 
 	~AudioMarkerProvider() = default;
 public:
-	/// @brief Return markers in a time range
+	/// @brief Return markers in a time range to render in audio display
 	virtual void GetMarkers(const TimeRange &range, AudioMarkerVector &out) const = 0;
 
+	/// @brief Return markers in a time range to snap timed lines to
+	virtual void GetSnapMarkers(const TimeRange &range, AudioMarkerVector &out) const { GetMarkers(range, out); };
+
 	DEFINE_SIGNAL_ADDERS(AnnounceMarkerMoved, AddMarkerMovedListener)
 };
 
@@ -143,10 +152,15 @@ class VideoPositionMarkerProvider final : public AudioMarkerProvider {
 	VideoController *vc;
 
 	std::unique_ptr<VideoPositionMarker> marker;
+	std::unique_ptr<VideoPositionRange> range1;
+	std::unique_ptr<VideoPositionRange> range2;
+	std::unique_ptr<VideoPositionSnapPoint> snap1;
+	std::unique_ptr<VideoPositionSnapPoint> snap2;
 
 	agi::signal::Connection video_seek_slot;
 	agi::signal::Connection enable_opt_changed_slot;
 
+	void SetPositions(int frame_number);
 	void Update(int frame_number);
 	void OptChanged(agi::OptionValue const& opt);
 
@@ -155,6 +169,7 @@ class VideoPositionMarkerProvider final : public AudioMarkerProvider {
 	~VideoPositionMarkerProvider();
 
 	void GetMarkers(const TimeRange &range, AudioMarkerVector &out) const override;
+	void GetSnapMarkers(const TimeRange &range, AudioMarkerVector &out) const override;
 };
 
 /// Marker provider for lines every second
diff --git a/src/audio_timing_dialogue.cpp b/src/audio_timing_dialogue.cpp
index 28d7ae53ec..873358d817 100644
--- a/src/audio_timing_dialogue.cpp
+++ b/src/audio_timing_dialogue.cpp
@@ -445,8 +445,8 @@ void AudioTimingControllerDialogue::GetMarkers(const TimeRange &range, AudioMark
 		boost::upper_bound(markers, range.end(), marker_ptr_cmp()),
 		back_inserter(out_markers));
 
-	keyframes_provider.GetMarkers(range, out_markers);
 	video_position_provider.GetMarkers(range, out_markers);
+	keyframes_provider.GetMarkers(range, out_markers);
 }
 
 void AudioTimingControllerDialogue::OnSelectedSetChanged()
@@ -897,8 +897,8 @@ int AudioTimingControllerDialogue::SnapMarkers(int snap_range, std::vector<Audio
 
 		snap_markers.clear();
 		TimeRange range(pos - snap_range, pos + snap_range);
-		keyframes_provider.GetMarkers(range, snap_markers);
-		video_position_provider.GetMarkers(range, snap_markers);
+		keyframes_provider.GetSnapMarkers(range, snap_markers);
+		video_position_provider.GetSnapMarkers(range, snap_markers);
 
 		for (const auto marker : snap_markers)
 		{
diff --git a/src/libresrc/default_config.json b/src/libresrc/default_config.json
index a4f0a1bf03..4029c76162 100644
--- a/src/libresrc/default_config.json
+++ b/src/libresrc/default_config.json
@@ -106,6 +106,8 @@
 			"Line boundary End" : "rgb(0, 0, 216)",
 			"Line boundary Start" : "rgb(216, 0, 0)",
 			"Play Cursor" : "rgb(255,255,255)",
+			"Current Frame Range" : "rgba(255,255,255,170)",
+			"Previous Frame Range" : "rgba(255,255,255,210)",
 			"Seconds Line" : "rgb(0,100,255)",
 			"Spectrum" : "Icy Blue",
 			"Syllable Boundaries" : "rgb(255,255,0)",
diff --git a/src/preferences.cpp b/src/preferences.cpp
index 9569bb1d67..8391052eb5 100644
--- a/src/preferences.cpp
+++ b/src/preferences.cpp
@@ -73,10 +73,10 @@ void General(wxTreebook *book, Preferences *parent) {
 	wxString autoload_modes[] = { _("Never"), _("Always"), _("Ask") };
 	wxArrayString autoload_modes_arr(3, autoload_modes);
 	p->OptionChoice(general, _("Automatically load linked files"), autoload_modes_arr, "App/Auto/Load Linked Files");
-	p->OptionAdd(general, _("Undo Levels"), "Limits/Undo Levels", 2, 10000);
+	p->OptionAdd(general, _("Undo Levels"), "Limits/Undo Levels", {.min = 2, .max = 10000});
 
 	auto recent = p->PageSizer(_("Recently Used Lists"));
-	p->OptionAdd(recent, _("Files"), "Limits/MRU", 0, 16);
+	p->OptionAdd(recent, _("Files"), "Limits/MRU", {.min = 0, .max = 16});
 	p->OptionAdd(recent, _("Find/Replace"), "Limits/Find Replace");
 
 	p->SetSizerAndFit(p->sizer);
@@ -136,13 +136,13 @@ void Audio(wxTreebook *book, Preferences *parent) {
 	p->OptionAdd(general, _("Auto-focus on mouse over"), "Audio/Auto/Focus");
 	p->OptionAdd(general, _("Play audio when stepping in video"), "Audio/Plays When Stepping Video");
 	p->OptionAdd(general, _("Left-click-drag moves end marker"), "Audio/Drag Timing");
-	p->OptionAdd(general, _("Default timing length (ms)"), "Timing/Default Duration", 0, 36000);
-	p->OptionAdd(general, _("Default lead-in length (ms)"), "Audio/Lead/IN", 0, 36000);
-	p->OptionAdd(general, _("Default lead-out length (ms)"), "Audio/Lead/OUT", 0, 36000);
+	p->OptionAdd(general, _("Default timing length (ms)"), "Timing/Default Duration", {.min = 0, .max = 36000});
+	p->OptionAdd(general, _("Default lead-in length (ms)"), "Audio/Lead/IN", {.min = 0, .max = 36000});
+	p->OptionAdd(general, _("Default lead-out length (ms)"), "Audio/Lead/OUT", {.min = 0, .max = 36000});
 
-	p->OptionAdd(general, _("Marker drag-start sensitivity (px)"), "Audio/Start Drag Sensitivity", 1, 15);
-	p->OptionAdd(general, _("Line boundary thickness (px)"), "Audio/Line Boundaries Thickness", 1, 5);
-	p->OptionAdd(general, _("Maximum snap distance (px)"), "Audio/Snap/Distance", 0, 25);
+	p->OptionAdd(general, _("Marker drag-start sensitivity (px)"), "Audio/Start Drag Sensitivity", {.min = 1, .max = 15});
+	p->OptionAdd(general, _("Line boundary thickness (px)"), "Audio/Line Boundaries Thickness", {.min = 1, .max = 5});
+	p->OptionAdd(general, _("Maximum snap distance (px)"), "Audio/Snap/Distance", {.min = 0, .max = 25});
 
 	const wxString dtl_arr[] = { _("Don't show"), _("Show previous"), _("Show previous and next"), _("Show all") };
 	wxArrayString choice_dtl(4, dtl_arr);
@@ -223,9 +223,9 @@ void Interface(wxTreebook *book, Preferences *parent) {
 	p->OptionFont(edit_box, "Subtitle/Edit Box/");
 
 	auto character_count = p->PageSizer(_("Character Counter"));
-	p->OptionAdd(character_count, _("Maximum characters per line"), "Subtitle/Character Limit", 0, 1000);
-	p->OptionAdd(character_count, _("Characters Per Second Warning Threshold"), "Subtitle/Character Counter/CPS Warning Threshold", 0, 1000);
-	p->OptionAdd(character_count, _("Characters Per Second Error Threshold"), "Subtitle/Character Counter/CPS Error Threshold", 0, 1000);
+	p->OptionAdd(character_count, _("Maximum characters per line"), "Subtitle/Character Limit", {.min = 0, .max = 1000});
+	p->OptionAdd(character_count, _("Characters Per Second Warning Threshold"), "Subtitle/Character Counter/CPS Warning Threshold", {.min = 0, .max = 1000});
+	p->OptionAdd(character_count, _("Characters Per Second Error Threshold"), "Subtitle/Character Counter/CPS Error Threshold", {.min = 0, .max = 1000});
 	p->OptionAdd(character_count, _("Ignore whitespace"), "Subtitle/Character Counter/Ignore Whitespace");
 	p->OptionAdd(character_count, _("Ignore punctuation"), "Subtitle/Character Counter/Ignore Punctuation");
 
@@ -253,6 +253,8 @@ void Interface_Colours(wxTreebook *book, Preferences *parent) {
 
 	auto audio = p->PageSizer(_("Audio Display"));
 	p->OptionAdd(audio, _("Play cursor"), "Colour/Audio Display/Play Cursor");
+	p->OptionAdd(audio, _("Current frame range"), "Colour/Audio Display/Current Frame Range", {.alpha = true});
+	p->OptionAdd(audio, _("Previous frame range"), "Colour/Audio Display/Previous Frame Range", {.alpha = true});
 	p->OptionAdd(audio, _("Line boundary start"), "Colour/Audio Display/Line boundary Start");
 	p->OptionAdd(audio, _("Line boundary end"), "Colour/Audio Display/Line boundary End");
 	p->OptionAdd(audio, _("Line boundary inactive line"), "Colour/Audio Display/Line Boundary Inactive Line");
@@ -310,7 +312,7 @@ void Interface_Colours(wxTreebook *book, Preferences *parent) {
 
 	// Separate sizer to prevent the colors in the visual tools section from getting resized
 	auto visual_tools_alpha = p->PageSizer(_("Visual Typesetting Tools Alpha"));
-	p->OptionAdd(visual_tools_alpha, _("Shaded Area"), "Colour/Visual Tools/Shaded Area Alpha", 0, 1, 0.1);
+	p->OptionAdd(visual_tools_alpha, _("Shaded Area"), "Colour/Visual Tools/Shaded Area Alpha", {.min = 0, .max = 1, .inc = 0.1});
 
 	p->sizer = main_sizer;
 
@@ -325,7 +327,7 @@ void Backup(wxTreebook *book, Preferences *parent) {
 	wxControl *cb = p->OptionAdd(save, _("Enable"), "App/Auto/Save");
 	p->CellSkip(save);
 	p->EnableIfChecked(cb,
-		p->OptionAdd(save, _("Interval in seconds"), "App/Auto/Save Every Seconds", 1));
+		p->OptionAdd(save, _("Interval in seconds"), "App/Auto/Save Every Seconds", {.min = 1}));
 	p->OptionBrowse(save, _("Path"), "Path/Auto/Save", cb, true);
 	p->OptionAdd(save, _("Autosave after every change"), "App/Auto/Save on Every Change");
 
@@ -403,7 +405,7 @@ void Advanced_Audio(wxTreebook *book, Preferences *parent) {
 	wxArrayString sc_choice(5, sc_arr);
 	p->OptionChoice(spectrum, _("Frequency mapping"), sc_choice, "Audio/Renderer/Spectrum/FreqCurve");
 
-	p->OptionAdd(spectrum, _("Cache memory max (MB)"), "Audio/Renderer/Spectrum/Memory Max", 2, 1024);
+	p->OptionAdd(spectrum, _("Cache memory max (MB)"), "Audio/Renderer/Spectrum/Memory Max", {.min = 2, .max = 1024});
 
 #ifdef WITH_AVISYNTH
 	auto avisynth = p->PageSizer("Avisynth");
@@ -435,8 +437,8 @@ void Advanced_Audio(wxTreebook *book, Preferences *parent) {
 
 #ifdef WITH_DIRECTSOUND
 	auto dsound = p->PageSizer("DirectSound");
-	p->OptionAdd(dsound, _("Buffer latency"), "Player/Audio/DirectSound/Buffer Latency", 1, 1000);
-	p->OptionAdd(dsound, _("Buffer length"), "Player/Audio/DirectSound/Buffer Length", 1, 100);
+	p->OptionAdd(dsound, _("Buffer latency"), "Player/Audio/DirectSound/Buffer Latency", {.min = 1, .max = 1000});
+	p->OptionAdd(dsound, _("Buffer length"), "Player/Audio/DirectSound/Buffer Length", {.min = 1, .max = 100});
 #endif
 
 	p->SetSizerAndFit(p->sizer);
@@ -468,7 +470,7 @@ void Advanced_Video(wxTreebook *book, Preferences *parent) {
 	wxArrayString log_levels_choice(8, log_levels);
 	p->OptionChoice(ffms, _("Debug log verbosity"), log_levels_choice, "Provider/FFmpegSource/Log Level", true);
 
-	p->OptionAdd(ffms, _("Decoding threads"), "Provider/Video/FFmpegSource/Decoding Threads", -1);
+	p->OptionAdd(ffms, _("Decoding threads"), "Provider/Video/FFmpegSource/Decoding Threads", {.min = -1});
 	p->OptionAdd(ffms, _("Enable unsafe seeking"), "Provider/Video/FFmpegSource/Unsafe Seeking");
 #endif
 
diff --git a/src/preferences_base.cpp b/src/preferences_base.cpp
index c1c0483d09..6b8295d653 100644
--- a/src/preferences_base.cpp
+++ b/src/preferences_base.cpp
@@ -126,7 +126,7 @@ void OptionPage::CellSkip(PageSection section) {
 	section.sizer->AddStretchSpacer();
 }
 
-wxControl *OptionPage::OptionAdd(PageSection section, const wxString &name, const char *opt_name, double min, double max, double inc) {
+wxControl *OptionPage::OptionAdd(PageSection section, const wxString &name, const char *opt_name, OptionAddArgs kwargs) {
 	parent->AddChangeableOption(opt_name);
 	const auto opt = OPT_GET(opt_name);
 
@@ -140,14 +140,14 @@ wxControl *OptionPage::OptionAdd(PageSection section, const wxString &name, cons
 		}
 
 		case agi::OptionType::Int: {
-			auto sc = new wxSpinCtrl(section.box, -1, std::to_wstring((int)opt->GetInt()), wxDefaultPosition, wxDefaultSize, wxSP_ARROW_KEYS, min, max, opt->GetInt());
+			auto sc = new wxSpinCtrl(section.box, -1, std::to_wstring((int)opt->GetInt()), wxDefaultPosition, wxDefaultSize, wxSP_ARROW_KEYS, kwargs.min, kwargs.max, opt->GetInt());
 			sc->Bind(wxEVT_SPINCTRL, IntUpdater(opt_name, parent));
 			Add(section, name, sc);
 			return sc;
 		}
 
 		case agi::OptionType::Double: {
-			auto scd = new wxSpinCtrlDouble(section.box, -1, std::to_wstring(opt->GetDouble()), wxDefaultPosition, wxDefaultSize, wxSP_ARROW_KEYS, min, max, opt->GetDouble(), inc);
+			auto scd = new wxSpinCtrlDouble(section.box, -1, std::to_wstring(opt->GetDouble()), wxDefaultPosition, wxDefaultSize, wxSP_ARROW_KEYS, kwargs.min, kwargs.max, opt->GetDouble(), kwargs.inc);
 			scd->Bind(wxEVT_SPINCTRLDOUBLE, DoubleUpdater(opt_name, parent));
 			Add(section, name, scd);
 			return scd;
@@ -161,7 +161,7 @@ wxControl *OptionPage::OptionAdd(PageSection section, const wxString &name, cons
 		}
 
 		case agi::OptionType::Color: {
-			auto cb = new ColourButton(section.box, wxSize(40,10), false, opt->GetColor());
+			auto cb = new ColourButton(section.box, wxSize(40,10), kwargs.alpha, opt->GetColor());
 			cb->Bind(EVT_COLOR, ColourUpdater(opt_name, parent));
 			Add(section, name, cb);
 			return cb;
diff --git a/src/preferences_base.h b/src/preferences_base.h
index 6643e642ba..25fa539353 100644
--- a/src/preferences_base.h
+++ b/src/preferences_base.h
@@ -33,6 +33,13 @@ struct PageSection {
 	wxWindow *box;
 };
 
+struct OptionAddArgs {
+	double min = 0;
+	double max = INT_MAX;
+	double inc = 1;
+	bool alpha = false;
+};
+
 class OptionPage : public wxScrolled<wxPanel> {
 	template<class T>
 	void Add(PageSection section, wxString const& label, T *control);
@@ -48,7 +55,8 @@ class OptionPage : public wxScrolled<wxPanel> {
 	PageSection PageSizer(wxString name);
 
 	void CellSkip(PageSection section);
-	wxControl *OptionAdd(PageSection section, const wxString &name, const char *opt_name, double min=0, double max=INT_MAX, double inc=1);
+
+	wxControl *OptionAdd(PageSection section, const wxString &name, const char *opt_name, OptionAddArgs kwargs = {});
 	void OptionChoice(PageSection section, const wxString &name, const wxArrayString &choices, const char *opt_name, bool translate = false);
 	void OptionBrowse(PageSection section, const wxString &name, const char *opt_name, wxControl *enabler = nullptr, bool do_enable = false);
 	void OptionFont(PageSection section, std::string opt_prefix);
diff --git a/tests/tests/color.cpp b/tests/tests/color.cpp
index 57d08a6127..128178c3a3 100644
--- a/tests/tests/color.cpp
+++ b/tests/tests/color.cpp
@@ -56,11 +56,13 @@ TEST(lagi_color, rgb) {
 	EXPECT_EQ(agi::Color(255, 255, 255), agi::Color("rgb(255,255,255)"));
 	EXPECT_EQ(agi::Color(255, 0, 127), agi::Color("rgb(255, 0, 127)"));
 	EXPECT_EQ(agi::Color(16, 32, 48), agi::Color("rgb(  16  , 32  , 48  )"));
+	EXPECT_EQ(agi::Color(16, 32, 48, 64), agi::Color("rgba(  16  , 32  , 48  , 64  )"));
 
 	EXPECT_EQ("rgb(0, 0, 0)", agi::Color(0, 0, 0).GetRgbFormatted());
 	EXPECT_EQ("rgb(255, 255, 255)", agi::Color(255, 255, 255).GetRgbFormatted());
 	EXPECT_EQ("rgb(255, 0, 127)", agi::Color(255, 0, 127).GetRgbFormatted());
 	EXPECT_EQ("rgb(16, 32, 48)", agi::Color(16, 32, 48).GetRgbFormatted());
+	EXPECT_EQ("rgba(16, 32, 48, 64)", agi::Color(16, 32, 48, 64).GetRgbFormatted());
 }
 
 TEST(lagi_color, ass_ovr) {