Never mind then. See if you can do a potting mix pH test and a mineral test of NPK to see what these detect, if any. For example, if the potting mix becomes too alkaline, the plant may be unable to absorb needed minerals or if watering has leeched out minerals, the plant cannot get needed minerals because there are none or too little and must be replenished. The closest to this whiting of blooms that I can remember was a post from someone whose Nikko Blue blooms in neutral soil close to or at 7.0 were turning whiteish to greenish to very light blueish but, that was at least 2-3 years ago so I do not remember where this happened or if the plant was potted or in the ground. The post may still be "out there" in the forum.

The money wasn't totally wasted if you've learned that plants have certain requirements to grow well. In this case, you planted shrubs that prefer only morning sun in a spot that had all day sun, and it's always more difficult to grow perennials and shrubs in pots since you have to choose a potting medium that suits their needs for drainage, moisture retention, and nutrients. For pots in full sun, look at annuals such as some of the annual Salvias, variegated culinary sage, golden creeping Jenny, million bells, or consider a pot of flowering succulents. As others have said, find a spot with morning only sun (3 hours is fine, and dappled shade will be fine if it's bright) and replant the the Hydrangeas. They've had a difficult year this season, but should recover next season if planted in an area more suited to their needs.

In warm locations like mine, it is very difficult to grow mophead hydrangeas in a western exposure, especially if they will get hit with afternoon sun in the summer months. You in Z5 are not as warm but, in the west side, it would be best to make sure that the leaves will get afternoon shade, little winds and plenty of moisture during the summer. Temps can also get hot in the summer when sunlight bounces off the house's walls and indirectly hit plants so inspect the location well. All that can be troublesome, especially for mopheads that typically like/need lots of water. However, things are relative. On the west side of my house, I grew a mac with golden foliage for several years. It was actually planted on the east side of a small pine tree that was growing close to the house so, the plant was both, on the west side of the house and on the east side of the small pine tree that provided it with afternoon shade. There was probably a 2-3' distance from the house to the pine tree. It worked fine for me. Eventually though, I moved it. I usually give hydrangeas more water than I give the other shrubs and, this location required that I water the plant by hand (no drip irrigation there). As you can suspect, after a few years, I grew tired of doing that just for one plant. So, I feel that west is always hard for camellias, azaleas and hydrangeas so I would not recommend it here but, you being in Zone 5, maybe... if you know that it will get afternoon shade, if direct and indirect summer sunlight is not intense in that location, if the spot does not get too hot or windy in the summer and if you can appropriately water the plant there. . If you decide to try, consider first growing it in a container so it can be easily moved. Keep it in the container for 1-2 years in the location you are considering... to see if that location 'works'. If not then just move the pot. If the plant likes the spot, consider winter protecting to get more reliable blooms.

Here the answers 1. Planted under tree (dappled sunlight all day), maybe one hour of direct sun light late evening 2. Mulched well to keep moisture , the area surrounding the plant was mulched using black anti-weed cloth and on top white gravel. 3. we had a lot of rains this spring and i think this helped 4. I added a cow manure , thrown half bag in the middle of the shrub (all old wood died and didn't survive the winter, i noticed a lot of new shoots from the ground. I cut all old woods. all blooms from new shoots 5. I applied a generous amount of Miracle Grow slow release ultra bloom around the root zone and in the middle of the shrub (i thought i am going to kill it hhhh) 6. I added Aluminum 3 times last year and 2 times this year (once a month) , both to the soil and as soluble in water. I ended up having mix of blue and pink.