We planted a quickfire tree in May. In early June it bloomed with this gorgeous white flowers. A month later the flowers are still white and maybe starting to brown a bit now, when do the flowers turn pink?
Just wait and it will eventually turn pink. I think that you may have the same heat wave that we do here, hence the browning of the flowers.
Or are you sure that it's a QF!? I have seen Limelight, Snow Mountain, Pink Diamond etc. trees but not a QF yet. Surely it can be done but you may want to check with the nursery where you got it from too!
Mine is just starting to get a touch of pink. I'm in southern Maine. The plant is in a pot, so it is probably 1-2 weeks ahead of a planted one here.