Color plays a part in the sales process for sure. Our old version of our website was VERY colorful. 6 main colors - green, blue, yellow, red, purple, orange - have a look on Archive.org from about 3 years ago.
During that time we used color in so many different ways from in-person (each wall in our office was a different color) and website pages/categories/CTAs, and of course we cross branded it to our YouTube videos, Facebook, etc. Now granted, we weren't doing neon or flashing lights on our site, but there was an explosion of color - very different than how our site looks today.
The reason we changed style was our story wasn't being told. We looked like an agency. We don't want to be an agency. We went from having 8 employees back to having just two of us, myself and my wife. Less babysitting
Can a colorful site convert? Definitely yes.
But that's all about color - the particulars of this was "dark patterns" which deals less about color and more about hidden actions that a user is forced or tricked into doing.