Remove dead color code (#3613)

## Description:

Remove dead code relating to colors.

## Please complete the following:

- [X] I have added screenshots for all UI updates
- [X] I process any text displayed to the user through translateText()
and I've added it to the en.json file
- [X] I have added relevant tests to the test directory
- [X] I confirm I have thoroughly tested these changes and take full
responsibility for any bugs introduced

## Please put your Discord username so you can be contacted if a bug or
regression is found:

DISCORD_USERNAME

babyboucher

src/core/game/UserSettings.ts

@@ -229,18 +229,6 @@ export class UserSettings {
     }
   }
 
-  getSelectedColor(): string | undefined {
-    return this.getCached(COLOR_KEY) ?? undefined;
-  }
-
-  setSelectedColor(color: string | undefined): void {
-    if (color === undefined) {
-      this.removeCached(COLOR_KEY);
-    } else {
-      this.setCached(COLOR_KEY, color);
-    }
-  }
-
   getFlag(): string | null {
     let flag = this.getCached(FLAG_KEY);
     if (!flag) return null;