how long do you wait after contacting a creator about a vendor giving out the wrong colored item before putting them on blast? it's been over 24 hours and they were online when i sent the nc. (they didn't have another contact person)

I'd send the NC again and give it another 24. Check the redelivery terminal in the store to see if it spits out the right colour.

Online doesn't always mean at keyboard and they might have missed your NC accidentally