The origin of that factoid has a bit of a convoluted history.
Back when Umbra was first revealed, people were confused why he had a “dark” name, since he was a good guy with light powers. Besides being a Latin word, “umbra” is used in English as a scientific term for the fully-shaded part in the middle of a shadow. That’s the definition you get when you look up “umbra” in the dictionary. However, the term umbra is taken from the Latin word umbra, which just means “shade” (it can also be used in the sense of “ghost,” which is also very fitting for Umbra’s character, since he can turn into pure light).
Anyway, back in 2006, everyone assumed that Umbra’s name literally meant “the darkest part of a shadow” in Matoran (which actually doesn’t make any sense, because although that is its meaning in English, there’s no reason to believe that it would have the same meaning in Matoran). When someone pointed out that “umbra” has dark connotations, Greg justified it by saying that it was a trick to confuse potential enemies.
Original quote: Official Greg Discussion | Page 126
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