setColorFilter not working
As much as I hate to answer my own questions I found the problem: I should've used:
weatherImg.setColorFilter(Color.WHITE, PorterDuff.Mode.SRC_ATOP);
It depends on what kind of filtering you want to apply. If yout want to apply a new color on an image with transparencies on it, that's what worked for me:
weatherImg.setColorFilter(Color.WHITE, PorterDuff.Mode.SRC_IN);
If you want to learn more about this PorterDuff filters, I found a goog article that helped me understand: http://www.ibm.com/developerworks/java/library/j-mer0918/ give it a read :)