First, welcome aboard! I shall look for your books.
While I've never bought a rod or blank solely on color, it's definitely a factor. I'm partial to the earth tones of brown, green, yellow, and red. I'm not attracted to blue, though I have blue rods. This question has come up before:
viewtopic.php?f=32&t=11949#p75457Some board members have posted polls. Board member mdraft, who operates a rod-building supply house, did a market survey about color on the board. You can search the board for "Color" etc. and find other threads.
To me, color is important, just not as important as performance characteristics.
Glad you're on the board. This was my first to join as well, and I've greatly enjoyed reading and making posts here.