Audio/Visual Electronics - side mirror turn signals

I am installing electric side mirrors with turn signals. I have the electric adjustment all wired correctly. There are 3 wires that control the turn signal mounted on the mirror. They are white, blue and black. I know the black connects to the black ground at the turn signal bulb. There is a green wire that controlles the blinker at the turn signal bulb. I guess that green would go to the white wire to the mirror. Where would the blue wire go?

I had a pair on my last ride. It had an extra wire that was a "constant". Basically if you wanted them to be on steady while your parking lights were on, and flash when you turned.

Hope this helped ya out.