Should the interior floor pans and firewall be painted the same color as the exterior of the car? When I took my car apart for repaint the interior sheet metal was painted a different color than the car. It looked like a semi-gloss gray color.

Yep, body color....not a great job or great coverage but definitely body color, at least the cars I've looked at. Year? Model? Plant?

Dave

Occasionally you would even get a totally different color floorpan due to the fact that the same spray gun was used for different colors. So, they would spray the floorpan first to get the previous color flushed out of the gun and lines.
I have seen a green Cuda with a partially blue floorpan from the factory.

The gray you saw would be the dip primer. I've seen cars with really good coverage and others maybe 50% covered. Really with the carpet installed, you won't see it, so I just use enough paint to seal the primer.

I have a one owner car undergoing its first restoration. The interior floor pan is close to but not quite the exterior color, F5 Limelight Poly green.

The main thing is the paint on the floor is low gloss. F5 is glossy.

Since the console is specified as Bayou Green Metallic low gloss in the factory service manual, I put the console on the floor to see if that's the color. It does not seem to be that color or that paint either.

So I put the instrument panel on the floor to see if they match. Nada.

The exterior and the floor pan are both green, just not the same green. Since my upper and lower door frames are F8 Ivy Green Poly, maybe the floor is F8? Nope, F8 is glossy and the floor isn't.

What's on my floor can't be matched to any other color that's on the car. But almost.

I'll leave it to my painter to empty his gun on the floor with whatever green is in the gun.

The firewall in the engine compartment is definitely painted with exterior body color, except where the painter didn't bother to lower his gun for full coverage and there is no paint. The firewall on the interior is just painted the same as the floor but not very high and below the dip line. That gray dip primer looks flat gray to me, not semi-gloss.

This photo shows the trunk with F5 gloss hanging on the garage wall at upper left. The floor pan is close but not that color.