Amiguinho
Try this:
FUNCTION TranspColor( oWnd, nRGB )
SetWindowLong( oWnd:hWnd, GWL_EXSTYLE, WS_BORDER )
SetWindowLong( oWnd:hWnd, GWL_EXSTYLE, WS_EX_LAYERED )
SetLayeredWindowAttributes( oWnd:hWnd, nRgb, 0, LWA_COLORKEY )
RETURN NIL