“The Sargasso Sea is a region of the North Atlantic Ocean bounded by four currents forming an ocean gyre” according to ye olde Wikipedia, for those of you are less educated in the ways of the sea.  If you need someone to explain what an ocean gyre is…well look that one up yourself, because I have no idea and that’s more research than I’m willing to do for a tropical shirt title.
Regardless of what all this fancy terminology means, this tropical is a vibrant yellow much like the floating seaweed pods the Sargasso Sea is famous for.  It even has a blue seaweedy pattern all over it!  Sure, the colors are the opposite of what they are in real life, but hey, the feeling it still there.
Fun fact: there are several species of fish that live in the Sargasso Sea that are only found in the type of seaweed that grows there.  Now I think that’s enough thinking for one day, wouldn’t you agree?  Don’t say the Mad Gringo never taught you anything!