"Paint your plane any color you like as long as it's white."
Step 7: Painting
After this, the only step left to do is apply the colored, top coat paint. In the automotive world, the pros normally apply a "primer/sealer" coat over the high build primer before applying the top coat paint. It's purpose is to seal the top coat paint from what's underneath it, like remnants of rust, oil, water, older paint, etc. (Think "car wreck.") It also provides better adhesion for the top coat paint.
It's a religious argument in the canard community as to whether or not we need the primer/sealer coat before our top coat paint. I'm no expert on the subject, but these are some of the guidelines I've heard:
(1) You generally don't need the primer/sealer coat if your high build primer and your top coat paint are from the same paint system from the same manufacturer. If your high build primer is from a different manufacturer than your top coat paint, or if you're not sure the two are compatible, then it's generally safer to go ahead and apply the primer/sealer coat.
(2) If any micro is showing at all (like if you didn't listen and sanded through the primer and into the micro), then you need to apply the primer/sealer coat.
(3) If your top coat paint covers well and flows out well, then the primer/sealer coat is generally not needed. If your top coat paint is very thin, then you can't go wrong applying the primer/sealer coat.
(4) You definitely need the primer/sealer coat if you've used a polyester primer.
Above all else, it's best for you to check with your local painting professionals.
Flying in Primer versus Paint
The other, bigger religious argument is whether to do the test flights in primer or in final paint. In general, if you expect to make some modifications based on what you learned during the test flights, it's probably best to fly the plane in primer. Just ensure that the primer is cleaned of all oils, bugs, and other residue before applying the top coat paint. You can buy surface preparation cleaners that do just that. You must also re-sand the primer to wake up the molecules in order to provide a good chemical bond for the top coat paint. Ken Miller suggests applying a sacrificial coat over the primer to protect it while flying.
Personally, I intend to paint the airplane inside and out before the first flight. It's not that I think my plane will be perfect or won't require some type of modification. But I do know that once the plane is flying, it's very hard to stop having fun and take the plane apart for painting! It's also very difficult to remove all the instruments and wiring in order to paint the interior. We flew my buddy's Long-EZ in primer for a year and a half before he decided to paint it. By that time the white primer was dull and dirty. The interior was never painted or upholstered. We'd cover it up at air shows so no one would see the dark brown from the EZ-Poxy.
But never say never, right? :-)
Exterior Paint Schemes
It's been said that the two hardest decisions in a homebuilder's life are (1) what to put in the instrument panel, and (2) what colors to paint the plane. Well, this is all about solving #2. My intention is to paint the plane white and apply some striping onto the sides and wheelpants. I'm thinking I'll use PPG Concepts "Bright White" and the "Elite" graphics shown below. The striping is a graphics kit available from any one of the hundreds of shops on the internet. Do a google search on "auto graphics" and you'll see what I mean.
Interior
Some basic thoughts:
1. Seats, arm rests, and consoles will be covered in a beige, tan, or light gray leather.
2. The visible fuselage interior surfaces will be zolatoned, but I haven't made up my mind as to the color.
3. The instrument panel will be covered in a light-colored formica overlay to complement the interior color scheme.