The colour of the link should indicate if you have viewed the page before, if you know why it is a different colour. Most people don't know why it is a different colour since most websites don't follow that standard anymore.
Another aspect to consider is the user changing their search term. This can result in a different snippet to be shown and with Google, sometimes a different title as well. It looks completely different. Some people might see the different colour link and their eye might be attracted to it, making it even more likely that a click may happen.
This could be a reason why people may be coming back to your page.