A blue t-shirt with a white outline of a fox has Firefox on the lower left side.
A brilliant blue, wrinkled t-shirt has a white fox sketched on it and Firefox on the bottom edge.
A Fiefox OS logo is on a blue shirt.
A blue t-shirt has a picture of a fox for the Firefox OS.
A badly creased blue top lays on a table and has an image of a fox on it and the words Firefox OS