Cant help with this named Hydrangia, but will go along with all the different ones I have growing here in Scotland UK, my climbing one has finnished flowering for this year, all the spent flowers are beginning to fade, but this one is always way ahead of my shrub type, as for my shrub types, these are in full bud as of now, just some colour starting to show, the pink ones are further on than the blue and white/cream ones, but that could have more to do with the position rather than the type, the blue ones are in bud but the flowers are still cream, only when they fully mature the clusters will the blue colour come forth, the cream ones are the same but will prob flower fully about a week after the others, this year I seem to have more buds/flower clusters than before, but we did have a very hot start to spring here and then a real cold spell, so far, we have had a wet cool summer, so this may have helped the shrub produce even more flowers than usual, if you look close at your shrubs, I would have expected you to have some flower clusters forming by now as they do take a wee bit of time/weeks to make a full cluster that will show colour about 3/4 weeks after that. hope this helps you some, good luck. WeeNel.
I'm in zone 5 and I have an Endless Summer. It just now has the start to one bud. You change the color by changing the acidity of the soil. I forget what you can by to change itto blue(maybe aluminum phosphate?)but last year I read burying pennies or pushing rebar into the soil will turn the flowers blue. Also pine needles should make it turn blue. Once mine open I'll let you know if the pennies and rebar worked(I did both).
Aluminum sulfate is what people usually use to turn them blue, lime will turn them pink. I don't think pennies and rebar are going to do too much, what is necessary to make the flowers blue is acidic soil with some aluminum in it, I'm not sure if pennies and rebar even have aluminum in them, and they won't do much to drop the pH of your soil so if you didn't already have acidic soil with aluminum in it, they probably won't change things much.
Well, I was halfway right on the aluminum thing...I figured the pennies and rebar was taking a chance, but I actually had those things laying around and was interested to see if it would do anything. If by some miraculous event they turn out all blue, I'll let you know. :)