For my taste, this is a perfect example of variegated thread is not at it's best in every pattern. While I do not dislike it, I think it is much prettier done in the solid thread. No matter how lovely the HDT, and this one by Sherry, Lady Shuttle Maker, is lovely, it just doesn't always work. This one is Grapefruit and I have tatted lots of pretty things with it. It's not the thread - it's the pattern. Where I start the pattern with a locked picot at the beginning of a chain, when you get back around and join, the two colors make it stand out too much. I scanned both hearts together so you can see the difference.
Most of you experienced tatters know this well. For any newbies, here is a good example. While I will always love tatting with variegated thread, especially HDT, sometimes it just isn't at it prettiest in certain patterns.