private DialogComponentProvider getLegendDialog() {

		LegendPanel legendPanel = new LegendPanel();
		legendPanel.setPalette(palette);
		OverviewColorLegendDialog legendDialog =
			new OverviewColorLegendDialog("Entropy Legend", legendPanel, getHelpLocation());
		return legendDialog;
	}
Kick when the colors have been changed.
Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/overview/entropy/EntropyOverviewColorService.java