$ gtk-query-settings theme <enter>
Upon enter, it displays the following:
gtk-theme-name: "Mint-Y-Dark-Orange" gtk-icon-theme-name: "Mint-Y-Dark-Orange" ! gtk-fallback-icon-theme: NULL gtk-key-theme-name: NULL gtk-cursor-theme-name: "Bibata-Modern-Ice" gtk-cursor-theme-size: 24 gtk-sound-theme-name: "LinuxMint" gtk-application-prefer-dark-theme: FALSE
On my desktop, the icons for some buttons in GnuCash were not visible and using above, I found that the theme style I had selected was
Mint-Y-Dark-Orange, but the icon-theme was
Mint-Y-Orange. After I corrected the icon-theme in
Mint-Y-Dark-Orange, the icons in GnuCash displayed correctly.
Additionally, to apply the dark theme on the desktop to GnuCash registers, in Gnucash, go to
Edit -> Preferences -> Register -> Graphics and uncheck the option
Use GnuCash built-in color theme. To re-enable the built-in color theme, recheck the box.