I love this! Its really cute <3

I've been having trouble trying to download and use the bases, I've tried downloading it in PNG and 'All files' and opening it in my usual art program (Krita) as Well as downloading SAI and trying to open there, and they dont come with layers!

The file isn't actually layered when you download it, so what you want to do is add a clipping layer over the base png (in pretty much any one of those programs that you have) image then set that layer to overlay. I'm not sure where it is in any program besides photoshop, but the way to change a layer to overlay is in the top left hand corner of the layer tool box. Then you should be able to color that clipped layer without any issues. However I would recommend that you do any edits to the base that you plan on making (adding hair, tail edits, adding wings, etc.) before coloring if you can help it. It makes it a lot easier to edit everything when you aren't trying to avoid messing up a good coloring job.

I hope that this helps a little bit. I'm not super up to date on art program jargon, so if what I said makes no sense I'm incredibly sorry.

It does! Thank you so much! <3