Q.Soil pH of hydrangeas
I have read that difference of soil pH yield different colors flowers in hydrangeas , but when I checked the soil pH of both the pink and blue color flower plants, they have the same soil pH.
I wanted to know why soil pH is same of blue and pink color plants?

It is likely to be in the "grey area" of between 6 and 7... This will usually make the blooms be anywhere from pink to blue, and in between. They really start showing colors either above, or below those two parameters. What method are you using to check soil pH? This can be difficult to do without the proper calibrated equipment, or previous knowledge on taking manual soil samples. Soil meters tend to give out false readings unless the conditions are just right.