Replace ColorRamp with HSLColor everywhere.

Fixes:
* Nuclear-purple color exploit.
* #3247.
* Removes a bunch of unnecessary color conversions every frame.

Caveats:
* The ramp range is now defined on the palette, so ramps can no longer be set per-player (may impact maps which define custom colors).
* It's no longer possible to perfectly recreate the original WW color ramps (I doubt we care).
* The old ColorRamp setting isn't migrated, so players will lose their color settings.

OpenRA.Mods.RA/InfiltrateForCash.cs

@@ -45,7 +45,7 @@ namespace OpenRA.Mods.RA
 			Sound.PlayToPlayer(self.Owner, info.SoundToVictim);
 
 			self.World.AddFrameEndTask(w => w.Add(new CashTick(toGive, 30, 2, self.CenterLocation,
-			                                                   infiltrator.Owner.ColorRamp.GetColor(0))));
+			                                                   infiltrator.Owner.Color.RGB)));
 		}
 	}
 }