When i save png, colors that're transparent displayed as black in windows explorer thumnail

it doesn’t hurt, but is there a way to fix this.

are you sure you are using the rgb mode and not the indexed, if you are using the index color mode them you need a mask index in your color palette(put it in the first position that will do the trick)

yes im using rgba, i think i found the problem, this occurs when switch betweeen dark mode and light mode(Windows10) too often and probably some opearting system code didn’t clear the cache.

in particular , the dark background is probably added by dark mode , and there’s also white background added by light mode, I have no idea if the latest windows have fixed this problem.

anyway, thanks guys.