I don't know much about the spotlight section but I am guessing the purple just means that you have visited the page. Other people will see blue until they visit the page. I must admit the visited link color is not especially appealing.
Thank you for your response Will! It's very odd though because even if I have a look at my page from someone else's PC, the titles are still purple (as though I've clicked on it) even though I haven't...hmmm