Filling transparent areas with a certain color

[testperson]

Hi,

sorry if this thread already exist. I'm searching for a way to fill transparent areas with a certain color (like the option "replace color", just for transparency/alpha).

Everything I could find is the other way around (from color to transparency).

Can someone help? I've read about the way decreasing colour depth. However if the transparent areas turn white this way and then I replace all areas which are white, I would also replace areas which originally were white and not transparent.

So how can I do this?

Kind regards

[xnview]

you can use 'change color depth' to replace alpha

[testperson]

Thank you