Its kind of different.
Black power means something different from white power.
This is how i look at it.
Black power is black people standing up for what they believe in.
White power is a KKK term.
It's because saying "white power" has a negative connotation to it. The term is mostly used in the act of suppressing the rights of black people. While "black power" was mostly used in the act of black people gaining equal rights to white people. Yes, it is a double entendre. But that's because a bunch of idiots in the past messed it up. However, I'm not going to stop you from putting it in you signature. People need to start getting over linking the phrase "white power" to a small group of white people that 99% of white people disagree with and for the most part hate. If it still doesn't make sense to you think about calling someone gay. 80% of the time it's used as a phrase to make people feel bad about themselves. It's only used 20% of the time for it's actual meaning.
White motherfucking power!!!!!!!