I have plans, of course, to improve the changes made a little more and take the mod to change the menu as well. But I'm too lazy.
For images to appear in the background of the skilltree screen, you need to use the Skill Tree Background Restoration mod: https://modworkshop.net/mod/16391
I am aware that some elements of the hud that my mod mod modifies end up with a strange white border, but I honestly can not find any way to fix it. my bad, guys.