Did You Ever Notice Princess Diana Was Obsessed With Blue Eyeliner? Princess Diana was one of the most photographed women in the world, but there's one detail you probably didn't notice: she always wore blue eyeliner. It was her signature look and certainly very of-the-moment in the '80s. Her makeup artist Mary Greenwell, however, was not on board. She admitted in an interview years later that she was the one who weaned Diana off the colored liner in favor of a more "soft" look. "Blue eyes should never wear blue pencil or shadow — it dulls your eyes," she said. We beg to differ. Even if Diana apparently "loved" the change and was "open minded about trying new looks," the blue eyeliner was such a fun beauty trademark (especially when you consider that being British royalty typically means being more conservative with personal style). At least we have photo evidence of her bold taste! Here, look back at 15 times Diana stepped out in the blue eyeliner — it might make yo..