Toolbar icon backgrounds come from the toolbar_blank.png image inside the theme. If your regular toolbars do have button images but this one doesn't, I don't know the difference here.
You can replace the current toolbar_blank.png image inside the theme with one from another theme or create your own. Instructions to how to unpack the theme to get into theme image resources are here.
Last edited by xpander; 11-20-2022 at 04:04 AM.
Reason: posts merged, thanks