When the word auburn was first brought into the English language circa 1430, it meant "white" or "yellow-white". Back then, there were a ton of different accepted spellings, including aburne, abourne, aborne, abron, and abrun. That last one is really important, because brun was the Middle English word for brown and people kept confusing the two. This resulted in the definition shifting over time to today's meaning of "reddish-brown", which is really cool! The original "white" meaning becomes more obvious as we move back through Old French auborne and Medieval Latin alburnus ("off-white") to the Latin word albus, which just meant "white" (you may recognize the name from Harry Potter; J.K. Rowling intentionally chose it for that definition). Finally, through Proto-Italic, the term eventually derives from PIE helbos, also "white".
Adam Aleksic, a rising sophomore studying linguistics and government at Harvard University, has been described as the internet's sixth most famous etymologist. He also has disturbing interests in politics, vexillology, geography, board games, conlanging, and law.