Is the firewall painted black or the same colour as the car. Same question for the inside of the fenders, black or the same colour as the car. Is there a website that explains how the car was painted coming out of the factory? Thanks

All of those areas are black, somewhere around 60% gloss. This info is not published anywhere, but questions about engine compartment colors are asked again and again. Try the search function, you should get lots of results. Color is only on the top portions of the fenders that extend down into the engine compartment.

The search window is a little cumbersome until you figure out the date settings. In my opinion, they are backwards from what you generally see, but you will get the hang of it.

Also look through tons of pictures. Many members (including myself) have a lot of picture links in their signature area.

I use the google such box at the bottom of the page. It seems to work well.

Maybe this link works.
google link

PM me an e-mail address and I will sent to you two High Performance Pontiac articles from 1999 that chronicle the concours restoration of a Plum Mist '67 RA I car that used to belong to PHS head Jim Mattison. They will provide you all the correct finishes for many of the parts on your car.