Add method to get stage from column index

osu.Game.Rulesets.Mania/Beatmaps/ManiaBeatmap.cs

@@ -3,6 +3,7 @@
 
 #nullable disable
 
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using osu.Game.Beatmaps;
@@ -60,5 +61,18 @@ namespace osu.Game.Rulesets.Mania.Beatmaps
                 },
             };
         }
+
+        public StageDefinition GetStageForColumnIndex(int column)
+        {
+            foreach (var stage in Stages)
+            {
+                if (column < stage.Columns)
+                    return stage;
+
+                column -= stage.Columns;
+            }
+
+            throw new ArgumentOutOfRangeException(nameof(column), "Provided index exceeds all available stages");
+        }
     }
 }

osu.Game.Rulesets.Mania/ManiaRuleset.cs

@@ -69,10 +69,10 @@ namespace osu.Game.Rulesets.Mania
             switch (skin)
             {
                 case TrianglesSkin:
-                    return new ManiaTrianglesSkinTransformer(skin);
+                    return new ManiaTrianglesSkinTransformer(skin, beatmap);
 
                 case ArgonSkin:
-                    return new ManiaArgonSkinTransformer(skin);
+                    return new ManiaArgonSkinTransformer(skin, beatmap);
 
                 case DefaultLegacySkin:
                     return new ManiaClassicSkinTransformer(skin, beatmap);

osu.Game.Rulesets.Mania/Skinning/Argon/ManiaArgonSkinTransformer.cs

@@ -4,6 +4,8 @@
 using osu.Framework.Bindables;
 using osu.Framework.Graphics;
 using osu.Framework.Utils;
+using osu.Game.Beatmaps;
+using osu.Game.Rulesets.Mania.Beatmaps;
 using osu.Game.Skinning;
 using osuTK.Graphics;
 
@@ -11,9 +13,12 @@ namespace osu.Game.Rulesets.Mania.Skinning.Argon
 {
     public class ManiaArgonSkinTransformer : SkinTransformer
     {
-        public ManiaArgonSkinTransformer(ISkin skin)
+        private readonly ManiaBeatmap beatmap;
+
+        public ManiaArgonSkinTransformer(ISkin skin, IBeatmap beatmap)
             : base(skin)
         {
+            this.beatmap = (ManiaBeatmap)beatmap;
         }
 
         public override Drawable? GetDrawableComponent(ISkinComponent component)
@@ -44,7 +49,10 @@ namespace osu.Game.Rulesets.Mania.Skinning.Argon
                 switch (maniaLookup.Lookup)
                 {
                     case LegacyManiaSkinConfigurationLookups.ColumnBackgroundColour:
-                        if (maniaLookup.StageDefinition.IsSpecialColumn(maniaLookup.ColumnIndex ?? 0))
+                        int column = maniaLookup.ColumnIndex ?? 0;
+                        var stage = beatmap.GetStageForColumnIndex(column);
+
+                        if (stage.IsSpecialColumn(column))
                             return SkinUtils.As<TValue>(new Bindable<Color4>(Color4.Yellow));
 
                         // TODO: Add actual colours.

osu.Game.Rulesets.Mania/Skinning/Default/ManiaTrianglesSkinTransformer.cs

@@ -3,6 +3,8 @@
 
 using System;
 using osu.Framework.Bindables;
+using osu.Game.Beatmaps;
+using osu.Game.Rulesets.Mania.Beatmaps;
 using osu.Game.Skinning;
 using osuTK.Graphics;
 
@@ -10,9 +12,12 @@ namespace osu.Game.Rulesets.Mania.Skinning.Default
 {
     public class ManiaTrianglesSkinTransformer : SkinTransformer
     {
-        public ManiaTrianglesSkinTransformer(ISkin skin)
+        private readonly ManiaBeatmap beatmap;
+
+        public ManiaTrianglesSkinTransformer(ISkin skin, IBeatmap beatmap)
             : base(skin)
         {
+            this.beatmap = (ManiaBeatmap)beatmap;
         }
 
         private readonly Color4 colourEven = new Color4(6, 84, 0, 255);
@@ -28,10 +33,12 @@ namespace osu.Game.Rulesets.Mania.Skinning.Default
                     case LegacyManiaSkinConfigurationLookups.ColumnBackgroundColour:
                         int column = maniaLookup.ColumnIndex ?? 0;
 
-                        if (maniaLookup.StageDefinition.IsSpecialColumn(column))
+                        var stage = beatmap.GetStageForColumnIndex(column);
+
+                        if (stage.IsSpecialColumn(column))
                             return SkinUtils.As<TValue>(new Bindable<Color4>(colourSpecial));
 
-                        int distanceToEdge = Math.Min(column, (maniaLookup.StageDefinition.Columns - 1) - column);
+                        int distanceToEdge = Math.Min(column, (stage.Columns - 1) - column);
                         return SkinUtils.As<TValue>(new Bindable<Color4>(distanceToEdge % 2 == 0 ? colourOdd : colourEven));
                 }
             }

osu.Game.Rulesets.Mania/Skinning/Legacy/ManiaLegacySkinTransformer.cs

@@ -8,7 +8,6 @@ using System.Collections.Generic;
 using osu.Framework.Audio.Sample;
 using osu.Framework.Bindables;
 using osu.Framework.Graphics;
-using osu.Framework.Utils;
 using osu.Game.Audio;
 using osu.Game.Beatmaps;
 using osu.Game.Rulesets.Mania.Beatmaps;

osu.Game.Rulesets.Mania/UI/Column.cs

@@ -11,7 +11,6 @@ using osu.Framework.Graphics.Pooling;
 using osu.Framework.Input.Bindings;
 using osu.Framework.Input.Events;
 using osu.Game.Rulesets.Judgements;
-using osu.Game.Rulesets.Mania.Beatmaps;
 using osu.Game.Rulesets.Mania.Objects;
 using osu.Game.Rulesets.Mania.Objects.Drawables;
 using osu.Game.Rulesets.Mania.Skinning;
@@ -68,9 +67,6 @@ namespace osu.Game.Rulesets.Mania.UI
         [Resolved]
         private ISkinSource skin { get; set; }
 
-        [Resolved]
-        private StageDefinition stageDefinition { get; set; }
-
         [BackgroundDependencyLoader]
         private void load()
         {
@@ -116,7 +112,7 @@ namespace osu.Game.Rulesets.Mania.UI
 
         private void onSourceChanged()
         {
-            AccentColour.Value = skin.GetManiaSkinConfig<Color4>(LegacyManiaSkinConfigurationLookups.ColumnBackgroundColour, stageDefinition, Index)?.Value ?? Color4.Black;
+            AccentColour.Value = skin.GetManiaSkinConfig<Color4>(LegacyManiaSkinConfigurationLookups.ColumnBackgroundColour, Index)?.Value ?? Color4.Black;
         }
 
         protected override void LoadComplete()