Can I go anywhere for a personal color analysis?

I have a few questions about personal color.

1. With personal color analysis suddenly gaining popularity, I've been seeing places offering diagnoses everywhere. Should I look for a place with certified experts or good reviews?

2. When I watch TV, they ask, "This looks better, right?" while doing the diagnosis. But I have a bit of a bad eye for style, so it looks good on one side and not on the other. Does the person doing the diagnosis make judgments based on fixed standards? Or do they make recommendations by taking my personal style preferences into account along with the color analysis results?

Actually, I think this also depends on the diagnostician's competence, so I want to get a proper diagnosis. I'm also curious about tips on finding such a place.