We all know Lavan was a bad person. He tried to kill Yaakov, he enslaved Yaakov, tried to cheat Yaakov out of his wages, he gave Yaakov the wrong wife, and many more. We even begin the hagaddah with a testament against him. If one would associate a color with him, it would be black, grey or some sort of dark color. For sure someone wouldn't associate him with white! So then why is the meaning of Lavan's name white?
This article explains
The name Laban means "white". According to the Kabbalah, Laban represents loben ha-elyon, the "supernal whiteness" that transcends all "color" and classification. Thus "Laban" embodies the power of transformation — because it is beyond classification, it bridges opposites and can transform a thing into its very extreme. This is how Balaam's divine gift of prophecy (our sages go so far as to equate his prophetic power with that of Moses!) could reside within such an evil person, and how, on the other hand, his virulent curses could be transformed in his very mouth into blessings, and this arch enemy of Israel even ends up issuing the most important of the Torah's prophecies (Numbers 24:15-25) — the promise of the future redemption by Moshiach.
An alternative explanation which I've often heard yet haven't pinpointed is seen on Wikipedia:
His name can also be seen as symbolic in this matter: it means "white", the visual representation of purity, without visible stain, symbolizing those without apparent evil motives whose actions nevertheless result in undesirable outcomes.