XmCascadeButtonGadgetHighlight(3) on Linux
The text e5a038fb0c12, as Debian 13 (Trixie), Debian 12 (Bookworm), Debian 11 (Bullseye), Debian 10 (Buster), Debian 9 (Stretch), Debian 8 (Jessie) shipped it.
A CascadeButtonGadget function that sets the highlight state "XmCascadeButtonGadget\%Highlight" "CascadeButtonGadget functions" "XmCascadeButtonGadget\%Highlight"