I do NOT understand Zazzle’s store design choices, but… https://www.zazzle.com/store/baitcon
There is one piece of art (<3 <3 <3 to Sarah Morrison) in various ink colors. I think with most of them you should be able to choose any underlying print item – esp. different shapes and weights of shirts – and color you want.
If there’s some combo you can’t make for yourself, let me know and I’ll build a new “product”.