I can not provide much info on HMS VICTORIOUS camouflage, but can answer one of your questions.
While researching the photo that showed what turned out to be HMS VICTORIOUS at Argentia, I found the following info.
Based on what is supplied on the ...
http://www.armouredcarriers.com ... website;
HMS VICTORIOUS ended USN operations and departed Noumea on 31 July 1943.
HMS VICTORIOUS arrived at Pearl Harbor on 9 August 1943, but only stayed for a short period and departed on 12 August 1943. Not likely she was repainted at this time.
HMS VICTORIOUS stopped briefly at San Diego to drop-off personnel, but since there were no major facilities at San Diego for working on a carrier, it is unlikely she was repainted here.
HMS VICTORIOUS arrived at Norfolk Navy Yard on 1 September 1943 and was there for two weeks (according to other records, she was in NorNY 3-15 September 1943) getting some US equipment (like SG radar) upgrades and having other USN equipment removed. I believe that this two week period would be the most likely place and period that she was repainted. Norfolk Navy Yard had and did continue to do work on ILLUSTRIOUS class carriers and quite likely had a supply of RN paints for painting them.
As an interesting aside, from 31 August 1943 through December HMS INDOMITABLE was also at Norfolk Navy Yard as seen in this close-crop view dated 20 October 1943. It appears that she is having some repainting done.