Improve star rating colour animations to match

osu.Game.Tests/Visual/SongSelectV2/TestSceneBeatmapTitleWedge.cs

@@ -57,6 +57,22 @@ namespace osu.Game.Tests.Visual.SongSelectV2
             });
         }
 
+        [Test]
+        public void TestRulesetChange()
+        {
+            selectBeatmap(Beatmap.Value.Beatmap);
+
+            AddWaitStep("wait for select", 3);
+
+            foreach (var rulesetInfo in rulesets.AvailableRulesets)
+            {
+                var testBeatmap = TestSceneBeatmapInfoWedge.CreateTestBeatmap(rulesetInfo);
+
+                setRuleset(rulesetInfo);
+                selectBeatmap(testBeatmap);
+            }
+        }
+
         [Test]
         public void TestNullBeatmap()
         {
@@ -90,22 +106,6 @@ namespace osu.Game.Tests.Visual.SongSelectV2
             checkDisplayedBPM($"{bpm * 0.75f}");
         }
 
-        [Test]
-        public void TestRulesetChange()
-        {
-            selectBeatmap(Beatmap.Value.Beatmap);
-
-            AddWaitStep("wait for select", 3);
-
-            foreach (var rulesetInfo in rulesets.AvailableRulesets)
-            {
-                var testBeatmap = TestSceneBeatmapInfoWedge.CreateTestBeatmap(rulesetInfo);
-
-                setRuleset(rulesetInfo);
-                selectBeatmap(testBeatmap);
-            }
-        }
-
         [Test]
         public void TestWedgeVisibility()
         {

osu.Game/Beatmaps/Drawables/StarRatingDisplay.cs

@@ -23,6 +23,8 @@ namespace osu.Game.Beatmaps.Drawables
     /// </summary>
     public partial class StarRatingDisplay : CompositeDrawable, IHasCurrentValue<StarDifficulty>
     {
+        public const double TRANSFORM_DURATION = 750;
+
         private readonly bool animated;
         private readonly Box background;
         private readonly SpriteIcon starIcon;
@@ -36,6 +38,12 @@ namespace osu.Game.Beatmaps.Drawables
             set => current.Current = value;
         }
 
+        /// <summary>
+        /// The difficulty colour currently displayed.
+        /// Can be used to have other components match the spectrum animation.
+        /// </summary>
+        public Color4 DisplayedDifficultyColour => background.Colour;
+
         private readonly Bindable<double> displayedStars = new BindableDouble();
 
         /// <summary>
@@ -139,7 +147,7 @@ namespace osu.Game.Beatmaps.Drawables
             Current.BindValueChanged(c =>
             {
                 if (animated)
-                    this.TransformBindableTo(displayedStars, c.NewValue.Stars, 750, Easing.OutQuint);
+                    this.TransformBindableTo(displayedStars, c.NewValue.Stars, TRANSFORM_DURATION, Easing.OutQuint);
                 else
                     displayedStars.Value = c.NewValue.Stars;
             });

osu.Game/Screens/SelectV2/BeatmapTitleWedge_DifficultyDisplay.cs

@@ -236,7 +236,10 @@ namespace osu.Game.Screens.SelectV2
 
                 updateDisplay();
 
-                displayedStars.BindValueChanged(_ => updateStars(), true);
+                displayedStars.BindValueChanged(_ =>
+                {
+                    starRatingDisplay.Current.Value = new StarDifficulty(displayedStars.Value, 0);
+                }, true);
                 FinishTransforms(true);
             }
 
@@ -330,17 +333,6 @@ namespace osu.Game.Screens.SelectV2
                 };
             });
 
-            private void updateStars()
-            {
-                starRatingDisplay.Current.Value = new StarDifficulty(displayedStars.Value, 0);
-
-                Color4 colour = displayedStars.Value >= 6.5f ? colours.Orange1 : colours.ForStarDifficulty(displayedStars.Value);
-                difficultyText.FadeColour(colour, 300, Easing.OutQuint);
-                mappedByText.FadeColour(colour, 300, Easing.OutQuint);
-                countStatisticsDisplay.TransformTo(nameof(countStatisticsDisplay.AccentColour), colour, 300, Easing.OutQuint);
-                difficultyStatisticsDisplay.TransformTo(nameof(difficultyStatisticsDisplay.AccentColour), colour, 300, Easing.OutQuint);
-            }
-
             private void computeStarDifficulty(CancellationToken cancellationToken)
             {
                 difficultyCache.GetDifficultyAsync(beatmap.Value.BeatmapInfo, ruleset.Value, mods.Value, cancellationToken)
@@ -360,7 +352,16 @@ namespace osu.Game.Screens.SelectV2
             protected override void Update()
             {
                 base.Update();
+
                 difficultyText.MaxWidth = Math.Max(nameLine.DrawWidth - mappedByText.DrawWidth - mapperText.DrawWidth - 20, 0);
+
+                // Use difficulty colour until it gets too dark to be visible against dark backgrounds.
+                Color4 col = starRatingDisplay.DisplayedStars.Value >= OsuColour.STAR_DIFFICULTY_DEFINED_COLOUR_CUTOFF ? colours.Orange1 : starRatingDisplay.DisplayedDifficultyColour;
+
+                difficultyText.Colour = col;
+                mappedByText.Colour = col;
+                countStatisticsDisplay.AccentColour = col;
+                difficultyStatisticsDisplay.AccentColour = col;
             }
 
             private partial class MapperLinkContainer : OsuHoverContainer

osu.Game/Screens/SelectV2/BeatmapTitleWedge_DifficultyStatisticsDisplay.cs

@@ -21,7 +21,7 @@ namespace osu.Game.Screens.SelectV2
 {
     public partial class BeatmapTitleWedge
     {
-        public partial class DifficultyStatisticsDisplay : CompositeDrawable, IHasAccentColour
+        public partial class DifficultyStatisticsDisplay : CompositeDrawable
         {
             private readonly bool autoSize;
             private readonly FillFlowContainer<StatisticDifficulty> statisticsFlow;
@@ -51,6 +51,9 @@ namespace osu.Game.Screens.SelectV2
                 get => accentColour;
                 set
                 {
+                    if (accentColour == value)
+                        return;
+
                     accentColour = value;
 
                     foreach (var statistic in statisticsFlow)