To start with, I strongly recommend this book.
link
Also, this link has the paint chips for the actual colors of the various navies that would also be a good place to start.
shipcamouflage.com/index.htm
Remember – the smaller the scale, the darker the paint will appear so for 1/3000 and particularly 1/4800 or 1/6000, you have to go lighter to get the right look.
Off the top of my head, I use Iraqui Sand, Dark Sand, Khaki, Beige Brown, and Deck Plank.
Beige Brown for the Germans and IJN who had fairly natural wood decks.
For the French and Italians where the wood was faded but not nearly as scrubbed as the Brits or Americans, I use the Iraqui Sand and the Dark Sand respectively.
All my US WW2 ships are in Deck Blue and I'm using that specific color from GHQ. For the Pearl Harbor early early war and any Brit exposed wood ( the Brits carried the camo patterns over onto the decks or used a dark gray fairly extensively) I use the Deck Plank.
On hull colors, the Japanese use a medium/dark gray based that was a bit different depending on which of the 4 yards did the painting. Testors has a Marine series with all 4 that really look good. The French very an overall light gray but otherwise , the US, UK and KM used various camo schemes that vary wildly and include many blues, grays and greens along with white and black and to a lesser degree, some browns.
What scale are you painting and how accurate do you want it to look?
