after trying a couple brands of touch up paint. I found a closest thing that match the shade of my stock white rims.

Dupli-Color

Scratch Fix 2 in 1

NG GM 434

it's not 100% match .. but pretty darn close.

 

is it too white or too dark? if too white, then you can get a tooth
pick and add a dot of enamel either yellow, blue, black to match your color.

 

Try these - they are supposed to be exact:
http://www.myminiparts.com/Products_...heelPaints.htm