Update: I tried a new flower food mix and my white roses turned blue

So I got this new flower food powder from a supplier at a trade show in Phoenix. It was supposed to be a super strong mix for long stem roses. I followed the packet, which said one scoop per liter. I used it on a batch of 50 white 'Vendela' roses for a wedding order. Two days later, the edges of the petals started showing this weird, pale blue tint! It wasn't the water, because other flowers in plain water were fine. I think the dye in the blue packet maybe leached out, or the mix had something reactive in it. Now I'm split: was it a fluke with that one batch, or is this powder just too risky for light colored blooms? Has anyone else had a flower food actually change a flower's color?