I look at "Color Profile" under the Image menu and it only had "Assign" and "Match." Of which I know nothing about. (Stil would be nice to have help manual)
Anyway, this time I restarted my computer without the Huion app and monitor turned on. Then I open ArtStudio Pro and opened the Photoshop document. Everything looks good as it should.
I started the Huion app and still, everything looks good. Turned on the Hunion tablet monitor and the problem returns in ASP.
Puzzling, because ASP is the only software that I have this problem with.
Ok, update. I looked under the Image>Color Profile>Assign and it was set to "None."