It is "normal" for white flowered macs to age to various tones of pink, some very pale; others quite deep. Depends on the cultivar, soil conditions and the amount of sunlight received. But ALL macs go through a series of color changes as the flowers age......I consider that one of their best features!!

Yes, I have seen it for sale late in the season and the blooms had tones of pink and some lime green too. I remember it because at first I thought it was mislabeled but one small bloom was still white-ish.