If you have a see-thru shell, like blue, green, red, whatever... you can remove the race way, the blue tube inside that goes down the feedneck and holds the motor and everything else, and paint it. I know somebody had a smoke hopper and painted the raceway yellow/gold to match his black/gold NME.
Dragon/Russian Legion/Ripper 3/Species/Vice Intimidators
Mirror's Edge/ Darq 7 / Red Edge
Silent Hill Cyborg