Welcome to the forum. Pretty sure a build card from Chrysler Historical Society (?) will give you the paint code, among other useful info. Can't say from experience, just what others on here have said. You can check to see if your engine# is original to your car by looking for the same# stamped on the frame.....for '49, I think somewhere on the outside left (drivers) side frame rail near the rear axle kick up.....someone more familiar with a '49 should chime in exactly where (my '38 has it just behind the axle kick up)....and will take some detective work looking for it if the frame hasn't been cleaned up.
Also, the search feature is very helpful, just type in "paint code", "build card", or something specific and you should get results. Make sure you are on the main forum page and NOT in a specific thread.
Check this out for build card info:http://www.ply33.com/Misc/buildcard