I'm a current junior in Boulder, Colorado. Like some others have said above, you can literally wear whatever you want, college is a more appropriate time than ever to do so. Out here, we have a mix of dirty hippie, hilariously overdone stereotypical frat, girls in sweatpants and uggs, and hipsters.
Find what suits you best. I have found my happy place to be a sort of "smart casual". Here's my usual getup:
Tops: Buttondown shirts in staple colors & patterns like white, blue, gingam, etc. For dressing down a bit, I wear henleys, white or grey t-shirts, thin sweaters, polo shirts, rugby shirts.
Outerwear: Harrington jackets, thicker sweaters (variety of necks including crew, v, and shawl), peacoats even though they are overplayed, camel duffle coat, barbour jackets, etc.
Bottoms: Usually just dark denim, chinos, corduroy, etc. Pressed, dressy trousers only for nicer occasions like dinners, dances, special evening events, etc.
Shoes: Plain white canvas sneakers, loafers, boat shoes, chukka boots, brown bluchers, some suede, and some nice leather fall/winter boots. Got Sorels for when its really snowy.
It's what most people my age consider well dressed, without coming across as "dadcore", dressing like an old man, dressing "too nice" ("why are you so dressed up?"), looking creepy like kids in trenchcoats over a black suit with a fedora, etc. I get a lot of inspiration from fall/winter casual americana style collections. Preppy stuff is also a pretty good start, once you get rid of the excessive "go to hell" pieces and go with more classic staples.
Here's an article that you might enjoy as well: http://putthison.com/post/34234663655/style-for-college-students-theres-no-kind-way-to
Cheers.