The RAF colours came out via the Ministry of Air Production (MAP). There is a book with those colours in it but it is of little use for Marine Craft as only the Yellow was used by them. The RAF Marine Section actually issued painting instructions under Kings Regulations as far back as 1928. The 1937 edition, which was still in force when the war started, had them with black hulls, BS381 32 Dark Battleship Grey superstructure and deck houses with white roof/tops. Decks were natural timber.
The 1941 edition changed the tops of deckhouses and superstructures as well as decks to BS381 56 Golden Yellow.
Then the RN started to control their colours first by confirming Kings Reg 2020 of 1941 under AFO 1518 of 1941. AFO 2077 of 1942 changed “For units operating on the E Coast S of the Humber and on the South Coast yellow is too dangerous. Decks and upperworks should be “the general tone” of the camouflage of the ship. Numbers are still to be yellow, VHF checkers still to be carried. RAF craft are still to carry roundel.” As non ASR boats at that time still had the pre war dark grey decks and superstructure, they could have used that. Alternatively, being based close to RN Coastal Forces they could have used RN paint. The RN is probably more likely as CAFO 4781 of 1942 had non ASR vessels including RMLs using Non Slip Deck Paint Dark Grey “like Admiralty Pattern 507A”. 507A was also a colour used by the RN for hulls and superstructure. Similar to Dark Battleship Grey but darker. In 1943, they switched to have the same deck colour as coastal forces were using which was primarily a dark Blue Grey known as B15.
Red checkers showed that vessels were carrying VHF radio and could converse with RAF aircraft. When more vessels carried VHF, the checkers were removed.
The Kings Regs when issued also had some drawings in them.
