One thing about red and yellow paint is that in my experience they always require more coats than other paint. They are both very translucent. If I were doing either of those colours I would likely do one or two coats of white before the red or yellow coats as a base.
That seems to be the case with my car! I have just put on the 4th coat, and it's still partially see through where there is light/dark contrast color underneath. I will do the normal wetsanding every 2 coats till it's totally solid color, then do one more coat before final wetsand and polish.
It is getting redder and shinier though, it's nice to see.
