Colour conformity pass.

osu.Game/Graphics/UserInterface/OsuTextBox.cs

@@ -13,6 +13,9 @@ namespace osu.Game.Graphics.UserInterface
 {
     public class OsuTextBox : TextBox
     {
+        protected override Color4 BackgroundUnfocused => Color4.Black.Opacity(0.5f);
+        protected override Color4 BackgroundFocused => OsuColour.Gray(0.3f).Opacity(0.8f);
+
         public OsuTextBox()
         {
             Height = 40;

osu.Game/Overlays/LoginOverlay.cs

@@ -33,7 +33,7 @@ private void load(OsuColour colours)
                 new Box {
                     RelativeSizeAxes = Axes.Both,
                     Colour = Color4.Black,
-                    Alpha = 0.8f,
+                    Alpha = 0.6f,
                 },
                 new Container
                 {