If you open a new lister, add a few tabs and set each tab Folder Options > Options > Folder Tab Color to a different color and then right click in the tab-tray > Groups > Save ( and / or Both Sides ) >
When you go to Right click tab-tray > Groups > Edit > Highlight -- the tabs will show properly but the colors will not.
HOWEVER, when you LOAD these tabs back into the lister.. the colors show up fine.. They simply don't show up in the tab-groups page unless you manually set them in the tab-groups page..
Those are two different color settings, one of which will override the other.
Tab Groups can set tab colors.
Folder Formats can also set tab colors.
Tab Groups also contain Folder Formats, so they have two ways to set a tab's color. (Not really by design as much as by accident of how things evolved. Tab colors were added to Folder Formats much later on, to enable tying colors to particular folders rather than particular tabs.)
Instead of setting the tab colors via Folder Options, right-click the tabs and use the Set Tab Color item in the menu. Then save the tab groups again.
The issue is the colors set by Folder Options do not show up when they are grouped; but they are saved and load when the tab loads... Why can't the grouped-tabs menu show the folder-options?
Because Folder Tab Groups primarily use the colors set on Folder Tabs.
Why not set them via the tab rather than via the folder format? It is fewer clicks, and you can also do it when editing the Folder Tab Group in Preferences.
Setting the color via folder formats generally only makes sense if you want to tie the color to a particular folder (not a particular tab).