Before it didn't work if just a color was set because it couldn't find "color_navbar_bg_hover".
Moreover, in odoo enterprise the navbar background color only worked for the main app menu,
now it works for both main app menu and the navbar of the apps.
If we change something with base.document.layout wizard, this will launch the colors computing even without changing the logo. This procedure will change the value of the colors if they were set by hand.
This change forces the user to press a button to recompute the colors and avoid possible undesired changes.
TT34902
