Colors
WebSite-Watcher can display a marker after the last change in a page. Here you can define the text and the color of that marker. The "Show last change marker" option can be enabled in the bookmark properties.
You should only use characters lower than ordinal value 128 (a-z, A-Z, 0-9) here since this text must be inserted into pages with different characters sets. Otherwise the last change marker might not be displayed correctly in all cases.
Define the color for removed elements. The "Show removed elements" option can be enabled in the bookmark properties.