Design by Humans are holding a special contest where the challenge is to design an awesome tee with just one color. Here is what they have to say about it:

…One Color Only is the theme but we do not expect you to go simple, show us your most beautiful art and coolest concepts. One color is all you are permitted but that color can be any color from the millions available. … Three winners will be selected. You can submit standard, oversized and all-over styles of printing and you can select any color t-shirt as your canvas. You can only use one color, use it wisely.

Prizes:

1. 1st Place: $1,500
2. 2nd Place: $1,000
3. 3rd Place :$750 + Goodie bag

Submissions close April 26, 2013.

Link: Design by Humans