Edit 17.6.2023: better solution is to edit and make gtk2 and gtk3 theme via config file.
https://coderwall.com/p/no3qfa/setting-gtk2-and-gtk3-theme-via-config-file
My ~/.gtkrc-2.0
##include ".gtkrc-xfce"
gtk-can-change-accels = 1
gtk-icon-theme-name = "Human"
gtk-theme-name = "Human"
style "user-font"
{
font_name="Ubuntu 12"
}
widget_class "*" style "user-font"
gtk-font-name = "Ubuntu 12"
My ~/.config/gtk-3.0/settings.ini
[Settings]
gtk-application-prefer-dark-theme = false
gtk-theme-name = Human
gtk-fallback-icon-theme = human-icon-theme
gtk-icon-theme-name = Human
gtk-font-name = Ubuntu 12
######################################################################
Caja´s default icon theme is ugly, so if not wanting to get headache, it is better to change icon theme. It can do easily via mate-appearance-properties. Open Terminal and run
mate-appearance-properties
