Does primer color really matter???
 

I'm not an expert on painting, but I'm just starting to get into it. I have been using regular grey primer. But i have seen on some shows on TV people using white primer to bring out the color of the base coat. Does the primer really affect the color of the base coat?

Yes. Ducati uses hot pink primer under red. Primer tinted the base color will make rock ship repair much easier.

So what color primer is the best for a guards red paint?

Primer colors are primarily to help with top coat coverage. A red top coat will cover a red colored primer faster with less coats than it would over a black primer.

Rule of thumb is to pick a primer that is close to your top coat, i.e. red primer for reds, green for greens, white for white and light colors, etc.

Some primers can be tinted to better match the top coats as well.

Ed