Hello, trivedi_south. The soil pH is not static and can vary a little from one year to the next. Your description of blue-ish suggests that it was originally acidic but not too too acidic. When the soil pH becomes more alkaline, the blue color will shift to purple and then to pink. There may even be a light blue, almost white, when the soil is almost neutral. Purple occurs in an extremely narrow range of pH between 7.0 and 6.5; it looks like your soil pH is in that range now. The exact point when purple occurs depends on which Mac one is growing. Injuries to the roots can also trigger changes in the bloom colors. Blooms with different colors on the same shrub happen when the soil pH around the shrub varies and some roots are able to absorb lots of aluminum and other roots absorb less.

Disturbing the roots changes the color.

And if this was recently planted/transplanted, it takes about 4 years for the color to stabilize.

Or if it was a potted gift hydrangea, growers can obtain the the color they desire by manipulating the content of the irrigation water. After it's in our garden, it will gradually adjust to its normal color, whatever that may be.

Thank you Luis! I am adding lot of mulch right now and watering it. The plant looks quite healthy just that it grew huge and it is kinda squished against the wall and a/c unit.

Thank you Jean. I planted it about 4ish years ago. I have two others that were pink in gifted pots and are flowering into blue/purple this year...so you are so right about how the color changed.

Thanks you kind folks. Appreciate all your help. will posts pics.

Purple "Endless Summer" hydrangea? I understand purple is mid-way between pink and blue. Does it work for any variety of hydrangea? I successfully changed a pink "Endless Summer" hydrangea blue. I would love a deep, dark purple. Would it be easier to buy a variety that is already supposed to be purple, ie: "Royal Purple" hydrangea?