Probably not colors simultaneously with numbers. If I understand correctly, the turret top colors were a Pacific Fleet thing. The numbers would be a holdover from earlier 1930s fleet-wide practice (anyone, correct me if I'm wrong on any of this).
These numbers are visible in many photos of battleships from the early to mid '30s, though often hard to see due to camera angles, distance, glare, and blurriness. I'm pretty sure I've seen them on cruisers also, but haven't been able to find any photos of that this morning. It's obvious there was no consistency in size, font, orientation, position (almost always on the roof of turret 2. Where on that roof... that's another matter), and color (light and dark varieties are discernible in B&W photos; might they have been yellow or blue, or red on occasion? Can't tell. Colors dictated by squadron? Possibly... but note Arizona's very large and dramatic shaded 39 - there's black
and white, and I can't recall seeing that style on any other ship. I think it was left entirely up to each ship)
I do occasionally see a dark turret top with a number (See this Idaho shot:
http://navsource.org/archives/01/042/014235i.jpg but I'm pretty sure that's a deck gray of some sort - note the same color on top of the armored conn. Side note, going on a little bit of limb here... perhaps the deck just below the conn is the same brown material (mastic?) used at the signal deck - it looks slightly different from the other horizontal color, and matches with the flag deck aft of the mainmast, which we know was brown, at least in 1940)
I can't recall seeing a turret top number on the #4 turret in early '30s photos; it may have been unique to the '42 New Mexico or perhaps a late '30s Atlantic fleet directive for identification marks at both ends (makes sense, from a Neutrality Patrol perspective I suppose.) I haven't noticed similar numbers on the Mississippi or Idaho at a similar time period, but then photos with the correct angle and clarity are few and far between. I expect they're out there, though.
- Sean F.