You would need to create the color palettes, write the code to get the cart to recognize and use them, and do everything in whatever free space is not used at the end of the ROM. GBColorizer changes essential game code in cartridges, which is why it "breaks" ROMs. Thomas Blind abandoned the project a long time ago, leaving his followers in the lurch- I myself had a full on colorization of MM1 that was waiting for a new version, and there was a total overhaul of Mario Land 2 that would only allow the player to go into one level before it corrupted the graphics.
Find Tom and he may help you.
But when I found him he simply chuckled at my feeble attempts at hacking.