Perhaps you could post some pictures!?

My gut reaction to your description is this: the buds are still developing so do not worry. You will see color soon. Hopefully.

Photos please!

Do you mean a green tinted or is it grass green (buds?)? Pictures would help.

Hydrangea flowers change color as they age. Often end up green possibly with red tinge.

Mine are pink this year from blue last year and I didn't put anything on the hydrangea, though I did lime my nearby grass. Sometimes, you don't even intend to do it. I like it though!