@Override
				protected void actionPerformed(NavigatableActionContext context) {
					ProgramSelection highlight = context.getHighlight();
					highlight = new ProgramSelection(highlight.subtract(context.getSelection()));
					setHighlight(context.getNavigatable(), highlight);
				}
Create the actions and add them to the tool.
Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/highlight/SetHighlightPlugin.java