Most of us are reasonably comfortable with the idea of carrying out usability testing on a website or prototype. We don’t always get the opportunity, but most people accept that it is a good idea. However, when it comes to a design concept, opinion is more divided. Some designers feel it undermines their role, a view that seems to be somewhat backed up by the famous “Forty Shades of Blue” episode, where Google tested which one of forty shades of blue to use for link color.

https://www.smashingmagazine.com/2020/06/test-design-concept-effectiveness/