College party theme idea or supply depends whether you are a freshman or have an established group of friends.
Freshman parties are a way of getting to know people when many students are away from home for the first time, separated from their childhood friends.
However one aspect of a college weekend is that there are loads of parties and most students will go from one to another.
That means whilst you can have a themed party a toga party is out, it is hard to go on to another party wearing a sheet.
All kids wherever they are like to dress up but there are so many parties to dress up for and so many themes. A CEO party is not fun after the first one. Have a fairy tale theme try red riding hood, as a college party theme it has a lot going for it, people can get dressed yup without being too dressed up. The moustache party can at least give the girls a laugh.
TV shows can offer a great party theme. "The Dukes of Hazzard" has spawned many examples. The boys come dressed in their finest wife-beaters and the girls come dressed in their daisy dukes and tank tops, all vying to resemble trash. Which leads to the white trash trailer bash, well you get the idea. It is always a good idea to waive the entrance price for those that have dressed up for a theme party as it does encourage the guests to make an effort.
Fortunately college parties depend more on music and alcohol than supplies, and even food is often in short supply, as the general rule seems to be to get as drunk as possible as quickly as possible.
However fancy dress can still be fun even if it is getting everybody to make their own tee shirt. College party ideas and supply does not need Albert Einstein to make it rocket science.