On my B6N2 part of the front wings are yellow. I had already painted the main color so i don't think airbrushing will work. How do i paint the yellow without 15 coats and leaving brush marks? HELP! This kit is almost done

Maybe use a low tack masking tape then airbrush. Probably the best way to have a uniform coat of paint.

Masking and airbrushing is really the simplest way.
Spray a clear coat to seal the masking tape from paint bleed, then I would spray a flat white to enhanse the following yellow color. Other wise the darker under lying color will propbably darken your yellow.

If you don't have an airbrush, you could looking for a sheet of solid decal film in the color you need and cut and fit that to the leading edge.

Thanks Grumpy. Would never have thought of spraying a clear coat over the masking tape. Brilliant!