Here's a pretty cool tee, if you like the All Stars Racing series. This one is for AllStars Racing: Transformed, but features only Sonic & his vehicle/s. The interesting bit is the all-over design & the fade from blue at the collar to white at the base. It shows his vehicle as the jet, the boat-like thing & the car in the foreground. The sleeves are all white, & the game's logo is in black & white sort of in the middle. Where was this available?
Here is a blue tee from Old Navy. It's sort of an aqua color, which is a bit less common. The design looks like it was meant to be a 'Polaroid" style instant camera picture, with the wide border at the bottom. But weren't all those always color? The photo here (and it is one) is in black and white. Look carefully though, and you can spot Shadow. He's there in profile, under Sonic's glove. This shirt is somewhat costly, at about 14.88 or so, & should be in the kids section. (MAY be too small for most people) Photo by CrystalSonicFan
This tee is from Old Navy. Remember, that usually their designs are exclusive to that store, so if you want it, you'll probably have to go there. This is a nice looking modern shirt, in a sort of mottled blue-gray. It has the modern logo at the top & 9 squares below. There's color art and newer 2013/2014 poses for Sonic, Tails, Knuckles & Shadow. But you can also see in just blue with screentone lines or dots a ring, a lightening bolt, some 4 pointed stars, a....time stone? & a Genesis/megadrive like controller. The controller doesn't go with the modern theme, but it still looks like it fits in anyway. (The Sol emeralds were longer than that? The regular & super emeralds are generally represented as 'diamondcut' or round (top view) so what stone is that they're trying to depict there in the corner?