IMHO paint it whatever color YOU like and to h^%l with what others think . That way if someone asks why that color it's because that's what YOU wanted, it's not someone elses choice
What we like doesn't matter, but what DOES matter is not making the interior choice FIRST. What I mean by that is fabrics are available in a limited range, so once you pick a general range of exterior paint, pick the interior fabric before you decide on the final shade of the paint which you can get/mix in unlimited shades. Nothing worse than seeing a nice paint job with a nice interior, but doesn't match. Example greenish blue paint won't work with purplish blue fabric, and red probably won't look good with burgundy paint. Complimentary colors may be more critical to me than others, as I spent 23 years in the art business, so color schemes catch my eye big time. Also, the fact that you're not wanting a metallic paint will make some of the choices rather bland imho.
If it were my car, I'd stick with the original color combination of shell grey and seamist. Those two colors would look very sharp with the original black and red interior colors. Plus, the Buicks of the early '50's look fantastic in two tone mainly (in my opinion) due to the stainless trim on the sides of the body. Another benefit....you don't often see the greys and silvers on these cars. Here's a picture of my '56 Caddy; it looks light grey but it's the original silver paint. If I ever paint the car, it will be in its original color.
I favor the first pic. some shade of a cream color. makes car look longer and more elegant un less you dont like a elegant car. Then do it in any of the other colors
Maroon, timeless color. Green comes and goes. I like silver but it doesnt show off lines like a darker color.
I think that using the Tyler Blue in place of the blue on the one @Moriarity posted with an off-white or ivory as you suggested could look really classy.
The Pennsylvania Railroad had a color called Brunswick Green that looked almost black under certain lighting conditions. I'm going to take that color, add some flake and a lot of clear for depth and call it Black Jade for my '57 Pontiac HT.
I'm a two tone fan. I happen to love a light top, I have Bombay Ivory on mine. I have close to or over 120 k miles on a 1949 1/2 ton truck that was for 20 years a dd/only vehicle. I live in the south, white reflects heat. I also have a sun visor that keeps the sun out and I just dig the way it looks.