White Residue on Top of Kegerator from BLC

[LoudounBrew]

Just clean out my beer lines on my kegerator for the first time. Some BLC mix spilled out on to the top of the kegerator. No big deal, I thought. I just wiped it off. But now there is a white residue that won't seem to come off. I've wiped it with a cloth and water and then with sanitation wipe with, I assume, alcohol, but the residue is still there.

Any ideas on how I get rid of this.

Thanks.