Years ago I worked for a computer store. I also redesigned their web site, but one of the owners had her own ideas...
Owner: I think you should use yellow and black.
Me: Why's that?
Owner: Because I've studied psychology and yellow & black makes people comfortable.
Me: Which products do you want to have featured on the site?
I redid the site without the yellow/black combo. This is the same company that asked me to create a newspaper ad using MS Publisher. Ugh.