(1) An altostratus cloud usually covers the whole sky and has a gray or blue-gray appearance.(2) You were probably looking at the sun or moon through a layer of altostratus clouds.(3) Where enough light shows through cirrostratus clouds to create shadows, it does not with altostratus .(4) The grey layer looks like and should be an altostratus although the fronts look different in the tropical regions.(5) From the ground this altostratus looks white or slightly blue and watery.
