This paragraph is from shipcamouflage.com
aircraft carrier flight decks be painted with 250N Blue Flight Deck stain. This was a dark blue gray stain that very nearly matched the 20B Deck Blue used on all other decks.
In respect to flight deck markings, these also underwent a change from the pre-war Chrome Yellow striping, to a less visible stain called 251N, a color almost identical to that of 5-0 Ocean Gray. On the LEXINGTON and HORNET in 1942 there was the use of solid deck lines in 251N. WASP and SARATOGA may have been similarly painted. By early 1943 the ENTERPRISE, SARATOGA, and RANGER were marked as follows: ENTERPRISE had broken yellow lines, SARATOGA had broken 251N lines, and RANGER had solid 251N lines.