typesofpreppy 
The world of preppy fashion is a big one. From the staid colors of L.L. Bean to the whimsical pastels on a Lilly Pulitzer shift, there is seemingly room for just about everyone at the table of prep. It may seem that plus sized women have been left from the table but I don't think that's entirely true.
What makes something preppy? Let's ask the iconic Lilly Pulitzer:
LillyLifestyleQuote

I describe preppy fashion as fashion that is appropriate for the occasion, is relatively simple, and is of good quality and taste.

It's a broad statement, but I really think it covers what preppy fashion truly is.