Decks, Patios, Porches and Docks - Help with resealing stamped patio

I have a stamped patio that is eight years old and has been resealed several times without problem. this year it needed it again and the original solvent based product was no longer available. We were told to wash the deck clean and strip the old sealer off with xylene, then to reapply a new, different, solvent based sealer called Diamond Clear. We did all of this only to have some areas of the patio turn white and some areas even stripped down to the bare cement? Other areas look great! What did we do wrong? It seems that the xylene stripped off not only the old sealer, but in some areas the color (color not integral; surface broadcast).

We are now told we can reapply new color to the stripped areas by mixing 1:1 ratio of xylene with the same sealant and adding 1 ox of powered color per gallon. It seems counterintuitive to do this based on the fact that the xylene may have stripped of the surface coating off before. Does anyone have any advice?