Tri-Colour combination help

We have always used a white foamer(soap)at our wash and red, yellow and blue for the tri-colour polish.Now we are about to change couple wash packages in which we are going to apply red soap for the top two washes and for the tri colour,If we have to take red out only other option we have is green and orange.So out of blue,green,yellow and orange which combination will give the good show or if there is any other colour available in the market.
Thanks

Green, yellow, and blue is not wise because yellow and blue makes green, so that would pretty much just make a car covered in green. If you dont mind mixing it your self you can make almost any color you want out of blue red or yellow (primary colors)I would stick with red yellow and blue as your tri colors, and go back to white for your soap. Keep it simple is what I always say.

IMO, the coolest combination I have seen in the magazine ads is neon green and purple.