1) Go to the colours submenu of the Game Options menu.
2) Choose the Ingame heading, then choose any of the presets.
3) You can see a white box for the backgrounds, and a white crosshair for all the other indicators.
4) Change any color setting by moving a slider. The slider value can be returned to the normal setting.
5) The preview should now display correctly.This bug is also present under the Maps heading.