Any of you guys ever played the Commodore 64 game Wizball? If you haven't you should. Here's what it's about:
Playing as Wizball (a spherical green spaceship), you have to go through various uncoloured worlds and have your trusted feline Wizkat (who is inside a smaller spaceship) collect droplets of Paint (Red, Blue and Green). By collecting this paint, you slowly fill up paint pots and eventually have enough paint to colour part of the level. So you have to go back to the lab. Cue the most awesome bonus level EVER in the history of gaming. After arriving at the lab, you mix the paints and return to the level. Voila! Part of the level is now coloured =D. There's three colour mixes per level to get, and 9 levels. You can always switch between 3 different levels.
If you haven't played it, go grab a C64 emulator and a Wizball ROM, and get playing. The theme tune is made of win, also.