Note to self you have to be smarter than what your working on. I forgot to put headers on before wiring plugs.
We've all been there brother.. No Worries! Have fun with it. I would just bend the wires around the bottom side of the headers, and learn from it for the next build. Don't get yourself down, you're doing an amazing job. Great Work!! You have to be able to laugh at yourself too!! I do it all the time!
As for colors like Yellows and lighter colors. I do many light coats, letting them dry between coats. Usually three, sometimes 4 coats. I don't sand between coats, unless I have a run, then I'll sand that out. Just make sure the surface is clean! I wet sand the flat surfaces when it's dry, and buff it with a polishing compound. Be really careful not to sand off any badges or fine details. I use soft cotton cloth to buff and wipe it clean I bought a baby blanket at Walmart and cut it up into small pieces, works great!