i submitted a few of them already but i wanna post them here and hear a little feedback, i always thought it would be neat to have shirts like these
Mask Shirts by ~optimusjimbo on deviantART
Mask Shirts by ~optimusjimbo on deviantART

both Mexican inspired, though I myself am not Mexican. I really dunno what color shirt either would look good on. on the skull one however the swirls can be removed but i like them.
Please don't take this post the wrong way. Your Samurai Jack idea and execution is amazing and I'd buy it in a heartbeat. It will probably be accepted just as it is. However, I feel that with a design like yours symmetry and consistency are very important, and I noticed a few a things:
http://imgur.com/bdlCJ