Changing Hydrangea colors

[disco]

Hey yall, been a long time since I posted anything but I have a question about Hydrangeas. Right now I have pink Hydrangeas and I have been trying to find out the best way to turn them deep blue/purple. I read organics like coffee grounds, vegetable peels, and fruit peels are the best way to get this without burning up the roots. There has been a bit of a drought in my area and some of the Hydrangeas in the area are so bright and vivid. Instead of them being pastel colors they are so bright. I will try to take pics of them when i get a chance, but I want mine to turn blue/purple.
Anybody have some opinions on this matter?

 

[Clint]

Acidic soil and aluminum. You probably have acidic soil down pat but you also need aluminum sulfate or some other aluminum supplement. It also depends on the cultivar sometimes.

You could mix in some peat instead of using coffee grounds. Would certainly smell better, hold more water, and not mold!