I didn't come up with the slogan “fishnet is not a color”, I must have heard it somewhere, but I can't find any references to it on the internet.

Heh ... for me, google found an exact match at https://forums.dukebasketballreport.com/forums/showthread.php?11660-Men-What-is-your-favorite-color-of-women-s-stockings.
Not sure if/how/why that's relevant ;-)

Cheers,
Rob