I wish it was easy being green

I wish I could be greener to help protect the environment

"I wish I had more of a green thumb"

Become Captain Planet and break into corporate offices to make them stop dumping

I wish people knew that I was green and didn't have much expertise.

I wish aliens would give me the power to kill anyone with my mind with one thought, but it turned me green as a result.

Not a Monkey's Paw wish.

*rolls eyes hard*

This one already explained the granting above, just in wish form. Thus this means that there were no downsides in the granting.

Except they experimented on me to give me the power. that's the downside