I would buy a tank in this. If you go with black the bright yellow looks great, but if you put it on blue or gray, talk to them about adjusting the ink color to add a touch more tan/mustard/ocher and a bit of white for a less intense yellow. Blue/yellow are pretty much opposites on the color wheel so it looks a bit funky to have any opposites side by side.
Try the blue with more like THIS YELLOWinstead of THIS YELLOW.
Trust me it will look a lot better! Just try it in Photoshop or something to see what I mean on the blue shirts.
Oh hey cool I just found out you can change the text to any shade you want! Okay let me try it, this is the shade I think would look better against the darker grayish blue . . .