When selecting Theme color Rose, the ▼ arrow icon on the application navigator does not display unless you hover over it.
This is by design of the theme, the color of the arrow is the same as the menu item's background color.
You can change the color with the following steps:
- Navigate to System UI > Themes
- On the List View, find the record named Rose and open it.
- Find the line with variable name $subnav-background-color
/* Background for expanded navigation items */
- Change the hexadecimal color value to a darker or lighter one, as you see fit.
- Save the change and reload your browser to apply the change.