The 32 bit PNGs are 24 bit color and 8 bit alpha channel. So the alpha channel can have 256 shades of gray. There are a couple of other PNG types.

We have had 120 inches of rain in some years. Lots of mud, too. I sort of lived in a swamp for a while. The water was about a foot deep on the road. Actually had a river running through the garden.

Rich