Is it possible to hack safari extensions with black/gray icons?

[ng0757]

Is it possible to hack safari extensions with black/gray icons?
I just don't like this blue icon, I hope experts can hack it into the same color as the built-in icons.

 

[frou]

I think it's mainly supposed to be a security thing, because it makes you aware at a glance that the ones which are lit up have access to the current page.