Need a script for user password change

[DGrandes]

I can't find this option, can you guide me where it is?

To change top bar color?

I´ve added in custom css:

body {
  
  background: #0f0f1e  !important;  
  
}

In LM? or you found such option somewhere in Safari?  Changing background in LM makes no difference.

Yes, in LM.

If i put this code in commentary, the top bar is gray, but if i put this code, the color is my background blue color.