How to change the color of hydrangea flowers.

[juinaout]

Thanks for your knowledge and sharing it, it's so clear and now I will try to change the color af my flowers  try

[Rudhayaini]

Thanks for the video. It made understanding the process easier. But I was wondering, I got myself a small mop-head 2 weeks back. When I got it, it was a sort of whitish. And then after a few days it started changing color and now it's lavender-ish and day by day it's becoming blue. So, I was wondering, does this mean that my soil is acidic? Or does it have something to do with the fact that I have been keeping the plant in a shaded area?