I can't stand my boyfriend's style...?

I love my boyfriend to death. And when I first started dating him, his sense of style was different from most guys I knew but I just figured it was cause he was from a different state. I didn't mind it too much. But as the years passed, the way he has started to dress makes me literally cringe inside.

For example, he would wear a shirt that has a lot going on everywhere with plaid shorts. And most if his shirts are one size too big for him. Or like when he found a shirt he really liked when we were shopping. It was a striped shirt with a lightning bolt on the middle and there was messy scribbles in the lightning. There was just too much going on and should've been banned or something.

I've tried everything. "i think this other shirt flatters you better baby" or "That shirt makes you look kinda scrawny cause it's so big. why don't you wear this shirt instead, it shows off your pecs." or "that's way too much cream in your outfit, why don't you change to jeans instead of khakis?" sometimes he listens but sometimes he actually thinks he looks good and seems like he doesn't trust my style. He's a good looking guy with a nice body. It's just his clothes that drives me crazy.

I hate being like a mom but it's kind of embarrassing. But I take pride in looking good when I step out the door. I believe your clothes tell others what kind of person you are. His just tells everyone that he has no clue. He wears colors and patterns that clash. Am I being too superficial? Should I just get over it? Or what other nice ways are there to improve one's style?