Hello Ashe and thank you for your prompt reply.
What is known about her colours from April(?) 42 is a little sketchy. Likewise reliable colour profiles. What is certain initially is that she was repainted in Measure 21 colours, and not 11 as I wrote. Apology for the error. Measure 21 called for all vertical surfaces to be in Navy Blue 5N, horizontal steel surfaces to be in Deck Blue 20-B while the flight deck was in the blue stain that was supposed to match Deck Blue. Some sources show the two parallel flight deck lines were in yellow but black is also a possibility. Since Enterprise, Hornet and Yorktown had all their deck lines in black by this time, the use of black rather than yellow on Lexington cannot be discounted. It is not clear that she received the number 2 on the flight deck at the prow and fantail. Photos of her are of not much help with this either. It turned out that the the blue colours used quickly turned to grey as the blue used was a notoriously fugitive pigment. I hope that is of some assistance to you. I have undertaken some serious research on the colours on these ships and found the Lex to be quite frustrating! Your ship models for il2 are truly inspirational by the way....
Cheers
Peter