I got it now, purple is opposite on the color wheel to yellow, meaning that it is every bit as obstinate and impossible to work with as its complement. I used primer, a white layer, thinned the paints, thickened the paints, and used 5-6 coats on every part and it STILL looks like this. Admittedly it looks a bit worse in these hi-rez pictures than it does in person under natural light but I amend my catch phrase: "Nothing painted yellow, OR PURPLE, ever looks good!"