Hello JHS and Will1957,
Where to start.. always a question.
The comment on modern paint matching is very interesting. Modern navy's seam to focus on Operation Efficiency and Economic Efficiency. So paint is delivered premixed and used as is. This thread focuses on the time frame of about 1901 to 1918. This was the transition from the Victoria Era of black, white and buff to the first use of grey by the RN. While the colours may have changed, it took much longer to change the Victorian attitudes where strict unquestioning exact compliance to orders was the norm. But first lets look at supply. Paint was not delivered premixed. Instead the First Lieutenant instructed the Ships Painter who worked with his crew using an Admiralty issued balance to weigh out Admiralty issued materials to make the paint for the ship on the spot to an Admiralty issued formula resulting in 100 cwt of ships paint. Victorian era attitudes where that if the Lieutenant got this wrong, he would not advance. In this era an Admiral was court marshalled for continuing gun target practice rather than returning to harbour to paint ship. So rather than the current Operation Efficiency and Economic Efficiency it was Strict Compliance that got you promoted. If you look at the pictures of the ships in the 1910 to 1914 time period they are immaculate with perfect paint. By 1918 where Operational Efficiency was taking over, some of the destroyers could look shabby indeed. And even HMS Erin, a battleship had shameful paint.
There are numerous posts in this thread that draw serious contention to the use of photos, models and art as a basis for colour. But here is another example. These shots were taken by me in the Transport Museum, the same day, using the same camera. The first uses the 'natural light' in the room and the second uses a flash.
Attachment:
GTM HMS Indomitable 1s.jpg
Notice the pronounced dark blue grey and also the odd greenish tint to the room.
Attachment:
GTM HMS Indomitable 2s.jpg
Notice with the flash that you get a neutral grey from the reflected balanced light of the flash.
So where to start... That was my problem with RN WW1 grey. So using an analytical balance, I mixed as per Admiralty formula the greys. Of course after 100 years I could not get Admiralty issued materials so I used mainly artist supplies as they come in small quantities. (Lead Oxide is considered a toxin and the less you have, the less you need to correctly dispose of.) The art supply lead and zinc oxides where also very finely ground which I feel is suitable in that current model colours use very finely ground pigments and so the colour matching would be more valid. Also checking the MSDS sheets for the art supplied compounds they were 100% Lead Oxide and zinc oxide so they should be as close a match to Admiralty supplied material as is available in this time period.
Do I feel the colours are perfect - nope. But I do believe they are a lot better place to start than any where else.
Cheers,
George