Works for me on Win 7 Home Premium 64bit. Only problem is if i alt-tab to windows and then go back to the game the graphics become horribly messed up.
I have the "kiddie colouring book" problem as well, but it seems its only triggered by either ALT+TABing, or if I get a popup, notice, badge, or anything that may appear in the background.
The only 'manual workaround' I've discovered for this is to:
1 Save the game.
2 Quit to the locomotion menu.
3 Click the 'singel/multiplayer mode' button and then close the window that comes up.
And voila the game reloads the color/textures or something and it all goes back to normal colors. After that you can load your game and continue playing.