Hi, Chris, this is late but haven't been able to be on here much.
I just finished 2 great books on Trafalgar, for anyone interested, they're "Nelson's Trafalgar", Roy Adkins, full of information on many aspects of life in the navy at the time, & "An Eyewitness to Trafalgar", Tom Pocock. Both have huge collections of letters by the seamen & officers who where there, English, French & Spanish, (some accounts a bit gruesome). Along with "blow by blow" accounts of the battle, facinating reading.
But most interesting, for here, is a passage by an English sailor; "the French ships are just like ours, black with YELLOW stripes"! Ad to this, after seaching for contemporary paintings of Royal Navy ships, by meticulous artists, you'll find the stripes are indeed invariably painted yellow. My Victory will remain yellow (ochre), I think I'll go with the word of one who actually saw it, (trusting he wasn't color blind) despite what "science" says.
Another note, it's said that when the gunports WERE OPENED, it produced the "Nelson chequer". This makes you think, were the port lids then yellow also?

Most welcome, Robin, glad you found them,(I've saved quite a bit of money checking Ebay first),we couldn't ask for more in first hand accounts, think you'll enjoy them. Forgot 1 other, "Young Nelsons", refering to young seamen & midshipmen, worth a read.
(Regarding the period paintings,I've painted in oils for many years, if one can't get their colors right, better find a new line of work!)