Change colour denoting expanded state to be gray rather than yellow

I always found the yellow colour very non-descript in this case. Gray
seems to work better?

osu.Game/Overlays/SettingsToolboxGroup.cs

@@ -39,10 +39,10 @@ public class SettingsToolboxGroup : Container, IExpandable
 
         public BindableBool Expanded { get; } = new BindableBool(true);
 
-        private Color4 expandedColour;
-
         private readonly OsuSpriteText headerText;
 
+        private readonly Container headerContent;
+
         /// <summary>
         /// Create a new instance.
         /// </summary>
@@ -71,7 +71,7 @@ public SettingsToolboxGroup(string title)
                     AutoSizeAxes = Axes.Y,
                     Children = new Drawable[]
                     {
-                        new Container
+                        headerContent = new Container
                         {
                             Name = @"Header",
                             Origin = Anchor.TopCentre,
@@ -117,12 +117,6 @@ public SettingsToolboxGroup(string title)
             };
         }
 
-        [BackgroundDependencyLoader]
-        private void load(OsuColour colours)
-        {
-            expandedColour = colours.Yellow;
-        }
-
         protected override void LoadComplete()
         {
             base.LoadComplete();
@@ -172,7 +166,7 @@ private void updateExpandedState(ValueChangedEvent<bool> expanded)
                 content.ResizeHeightTo(0, transition_duration, Easing.OutQuint);
             }
 
-            button.FadeColour(expanded.NewValue ? expandedColour : Color4.White, 200, Easing.InOutQuint);
+            headerContent.FadeColour(expanded.NewValue ? Color4.White : OsuColour.Gray(0.5f), 200, Easing.OutQuint);
         }
 
         private void updateFadeState()