GMC66 - thanks for your reply. I understand what you're trying to do.
I'm doing a frame off on a T-Bucket. Bright colors on T-Buckets seem to be the norm these days. Most of the new buckets I see these days are mono-colored. Chassis / engine / trans / driveline colors match body color. Some colors look great this way and others don't. I've seen all yellow, orange, dark green and dark blue Ts. I think they all look great. I'm not so sure something like some wild lime green would work (sure could see it coming down the road though!), but everybody has a different take. Do what makes you happy.
Anyway, I was having trouble making up my mind, so I let the wife decide. Her decision was glossy black chassis with lots of chrome components, same black on engine / trans / driveline, and Chrysler Viper Red body with dark grey or black interior. So that's what it's going to be, and that problem is now considered solved LOL!!
By the way, the POR-15 system looks like a good possibility for the black chassis components on my ride, which is why I was interested in other folk's experiences with it. Because the diff housing will be highly visible on this car, it seemed that painting it last made sense. I just didn't know (and still don't) if the POR-15 degreaser and metal prep will harm the seals if they get exposed to it.