THanks, I googled "hydrangea" and found the answer. I copied the info: "In acid soil the blooms will be blue, pink flowers in alkaline soil, and white in neutral. The flower colors may be controlled by adding aluminum sulfate to the soil prior to budding to produce or keep blue flowers; or by liming or adding quantities of superphosphate to the soil to produce the pink ones." I'd like to add my 2-cents worth to say that the drought has adversely affected things in a big way too.

Neither, not a phase and it cannot morph :) It's either a hydrangea with typical hydrangea flowers, or your hydrangea has died and something else is growing there.

From the shape and configuration of the sepals, it looks a bit like 'Fuji Waterfall' (syn. 'Fujiotaki'), which Dirr describes as a "loosely configured mophead". He goes on to describe the flower color as white suffused with blue in acid soils or pink in more neutral soils. Coloring of mature flowerheads can be rather variable depending on climate, amount of sunlight and watering conditions, but the greening followed by reddish tones is not uncommon on a lot of different hydrangeas. A photo of the shrub in blossom during the growing season might be more helpful. And there seems to be some confusion in the labeling of plants with this name - often 'Fuji Waterfall' is described as a lacecap with a cluster of fertile flowers surrounded by the cascading sterile ones. Dirr's photo shows only a loose cascading mass of sterile florets but even fully mophead varieties tend to hide a few fertile florets here and there. I'm not at all convinced that there are not at least two plants going by this name, one also referred to as 'Fireworks' ('Hanabi') or sometimes 'Shooting Star'. These names tend to be used interchangeably but there are hydrangea authorities (Dirr and Barry Yinger among them) who are firm that these are distinct plants.

These florist hydrangea blooms may be forced to bloom blue, purple or pink by the wholesaler. You can also see them white. But after the bloom gets "old" then it begins a series of color changes that add green and-or pink tones and finish turning brown. If you do not like the bloom, you can cut them off. And in moderate zones, you can try to grow them by planting them in morning sun and afternoon/evening shade. I bought one hydrangea from Kroger's with unusual blooms 3-4 years ago and planted it. Still with me. It is sensitive to cold so I try to protect the ends of the stems in winter so the invisible flower buds that develop in July-September will not get zapped (they open in the Spring). If you decide to grow the hydrangeas, look for a place where they get shade in the summer afternoon. I would add organic compost to the soil if the soil is sandy. And be prepared to water a lot in sandy soil (sand drains "too well"... ha!). Water when a finger inserted into the soil feels dry. Growing them in pots is also another option, provided you can remember to water the pot as needed. Ha! That is my weakness. I forget to water potted stuff... sigh... ;o)