Hi:

I'm dealing with this right now. These WWII navies & the Soviet fleet are simply not well covered.
WEM used to have some colours for some of these fleets but I believe they have been discontinued.

Here's what I have found to date:

French Navy(Pre-war-1940-Vichy Regime)

Early war light gray Vallejo 990 + 919 Light Grey + Foundation White Mix 1:2

Soviet Navy

991 Dark Sea Gray
992 Neutral Grey)

ORP (Polish fleet)

Tamiya XF80 “RN Light Grey”
Tamiya XF67 “NATO Green” (Subs)

Hope this helps.

Regards

Peter M the WWII Task Force 400 Shipguy.