I'd like to see a sign like this in public somewhere. The time is right for it.

What about seeing this in public? Leviticus 18:22 says so.

I would do it differently than you have done it. Your symbol might be interpreted by others as just "no rainbows" and God created rainbows. I would have a circle and a slash over two male gender symbols right next to each other, next to a circle and a slash over two female gender symbols right next to each other.