Hi Peter,
If it's of any help, during the same period Colonel Fawkes noted the colour schemes of the 74's at the Battle of the Nile,1798 (Culloden & Theseus both being Culloden Class 74's, although this might not be significant when considering colour schemes).
The British fleet at Abu Kir Bay
Alexander, Audacious, Bellerophon, Defence, Orion - Plain yellow sides.
Goliath - Light yellow sides with black streak between the upper and lower gun ports.
Culloden - Yellow sides with two small black streaks between the upper and lower deck ports.
Majestic, Swiftsure - Yellow sides with a black streak between the upper and lower deck ports.
Theseus - Light yellow sides with a black streak between the upper and lower deck ports with hammock cloths yellow and ports painted on them to resemble a three-decker
Vanguard - Yellow sides with a black streak between upper & lower deck ports.
Minotaur - Red sides with a black streak between the upper & lower deck ports
Zealous - Broad red sides with small yellow stripes.
It appears that the yellow was defined as being light yellow or canary yellow; an earlier darker yellow was not popular due to making the ships look 'dirty'.
Various articles that are great for information on ship colours are;
An Artist's Notes at the Battle of the Nile - Mariners Mirror (1914) - Original reference to Colonel Fawkes
The Application and Scheme of Paintworks in British Men-of-War in the Late Eighteenth and Early Nineteenth Centuries - Goodwin, Mariners Mirror 2013
Pitch, Paint, Varnish and the Changing Colour Schemes of Royal Navy Warships, 1775 1815: A summary of existing knowledge - Vale, Mariners Mirror 2020
http://www.larsonweb.com/Transfer/Miniatures/Sail/NAPSHIPS.htm
Mickey