PixelGetColor on background Window

[AzgarD]

Hello guys. So i'm using the following function to detect a change in the screen by using the PixelGetColor function, that by the way, is working fine, but now i need to detect that pixel color change in a background window. That can be done? Thanks guys.

 

Func ApertaF4()
        $pix =  $corpix
    While $pix = $corpix
        Sleep (300)
        ControlSend("1 - STC (10.31.9.100)", "", "", "{F4}")
        $pix = PixelGetColor($px,$py)
     WEnd
     VelocidadesVelox()
  EndFunc   ;==>ApertaF4