After posting my own question about what colors work best about two weeks ago, I got a very helpful response. Here's what I've been using along with some notes:
All tanks were primed using Rustoleum's "Hunt Club Green" satin (semi-gloss), which at $3.50 USD a can does a very good job, as well as being more affordable than the Army Painter color. It's a little "brighter" (more blue) than I really wanted, but that gets muted when one applies a good wash. I overpainted most of it with the very similar Vallejo and Reaper colors, but that was a personal choice.
FCM-36: Vallejo Green Ochre 914 base, & Luftwaffe Cam. Green 823 for blotches. Reaper Muddy Olive would also work for the spots. Tracks are Gun Metal or Iron I used an Adiken paint for this, but just about anything will do. The depictions of some of these tanks show that the upper portion of the turret has either a sky blue or light green area – perhaps meant to break up the silhouette. I first used some 25-year-old Polly S Avocado, but switched to Reaper Olive as it looked better (combination of color and coverage).
Somua: Vallejo Cam. Green for the most part. Reaper's Muddy Olive for the upper surfaces. There was more of a difference between the two greens before I gave it the wash so if I was doing more tanks, I'd mix in a little Reaper Olive to lighten it up. The brown is Vallejo 846 Mahogany Sand and the borders between colors was done with a Sharpie permanent marker.
Char B: Vallejo Cam. Green, Mahogany Sand and Reaper Olive (it looks to be the closest to the Seafoam Green/Light Avocado color used in the French schemes. The Ochre is actually a 2 to 1 mix of Reaper Olive with Vallejo Green Ochre in this case. I'm using Minitracks/Trackstory's illustrations for reference and they're showing a greener ochre on these tanks than what is used elsewhere. Again, the colors were outlined with a permanent marker.
There seems to be a recent line of thought that says that the areas usually depicted as being ochre on some French tanks could possibly be the Seafoam Green color instead.
If you go with the ochre, you can also use the German DunkelGelb or one of the yellower versions of SandGelb. The FCMs ochre is pretty close to the color I created mixing Tamiya Dark Yellow and Desert Yellow in a 2-to-1 ratio.
Wyatt