It's an odd issue. We can try to test if the issue is caused by any configuration in the user's directory or if there's an issue with any gnome or kali-themes package.
Try creating a new user with sudo adduser {username}, then login to that new user and change the settings there. Are they still being reverted after reboot?

this issue still not fixed as just changing automatically also when kali starts / boot everytime icons and theme revert to default

Oh, know I see what happens. That's my fault sorry.
I modified gnome so that when you change the theme (and also when gnome-shell restarts, that's the main cause of the issue), it sets all the themes to match the new color. So it overwrites the custom themes :(
Thanks for your report, I'll fix this ASAP

hi @daniruiz ,sir May i know in which update this bug will fix as i am very frustrating as in recent update it did not fix issue

Do not complain about how long it takes to fix a bug. Remember: the developers are volunteers with day jobs, which are not fixing your bugs for you.

https://www.kali.org/docs/community/submitting-issues-kali-bug-tracker/

I've just fixed this bug and the update should be ready in kali-rolling in a few days
https://gitlab.com/kalilinux/packages/gnome-shell/-/commit/ff4094b224ffe62dc98f66d6da4b2667646a83a3