If you had named your OS, as well as the version of it, plus additionally the version of Krita you use and from where it stems, I could have given a far better, even a definitive answer. That is Information you are required to name with support requests. Is it so hard to play along the rules of this forum?
Theoretically you can use the Plugin: Theme Creator Extension to manipulate them. But if you are using Android, you only can use already created schemes, if, yes, if, your Android device is not one of those crippled new devices that at best make a good job as doorstop, which also seem to depend on the manufacturer of it.
Michelist
In case you use an Android device follow this description to import color schemes. If you are lucky, your Android allows it:
If your Android is an older one, so up to Android 10, there is a good chance to import it into your Krita, but the newer Android and the cruder the manufacturers OS-Plug additionally put over it the smaller the chance.
Way one is the same as on every OS, open Krita’s resource folder out of Krita via Settings > Manage Resources... where you have to click the button Open Resource Folder which will then open the resource folder (theoretically), if that works for you, you have nearly won! Now you have to enter the folder color-schemes and copy the color scheme files you want to import into that folder.
Please try that first with the Android file manager, if that won’t work, you can go and download the free of charge file manager Total Commander (from Ch. Ghisler!) from the Play Store, that is a two pane file manager where you can put the files to copy in one pane and open the color-schemes-folder in the other, if you are lucky, then Android allows copying the files with Total Commander.
And there is a second way to reach your resource folder if it does not work directly out of Krita:
Alternatively, you can browse with your file manager/Total Commander to the path/folder that is shown to you in Krita, in the tab
Resourcesthat you will find via the menuSettings>Configure Krita>General, it is the tab at the right end.
Here you see where to find this as example on Windows, I’ve highlighted the path, you need to browse to the path that is shown in there in your Krita:
If you are able to reach that folder you have to do the same what I already wrote above, copy the unpacked color scheme files into the folder color-schemes.
Once the files are copied into the folder color-schemes, you must start/restart Krita two times and should find them then under Settings > Themes.