It's not too late!
Melt / liquify the wax again and add 2 or 3 drops of concentrated sulfuric acid, stir and it will turn yellow in a few seconds.
I have seen that demonstrated as a part of a beekeeping course in Germany in 1988. They said that the reason for the discolouration is a chemical reaction through contact of the liquid wax with corroded iron parts of the melting equipment. He dipped a rusty nail into the wax and it turned back to the green colour, then added the sulfuric acid and it became yellow again!
Regards
Reiner
P.S.: We are talking about an amount of 10kg of filtered and settled wax from a steam melter here, impurities or propolis in the wax are a different thing.