Does it look bad to mix'n'match different designers in an outfit?

So long as the colors match I mean. I don't just mean mix a couple different ones at a time, but like everything I wear is by a different designer some days. Case in point- light brown Guess hat, black chanel mother-of-pearl sungles, light tan suede Guess coat, baby pink burberry scarf, True Religion woodstock jeans, pink D&B east/west handbag and mocha Ugg upsides. The only matching brands are the hat and jacket lol. But I heard it's bad to mix too many at once and wondered if it was true