Over the winter, I read Craig LeHoullier's new book, Epic Tomatoes (2015, Storey Publishing). I was dubious that I could read an entire book about nothing but tomatoes, but Craig's book is compelling and inspiring; it influenced me to grow a much wider variety of tomatoes than ever before. His focus is on "heirloom" or open-pollinated varieties rather than hybrids. I've learned that if I'm willing to compromise on appearance and shipping/storage qualities, I'm likely to gain in fantastic and unique flavors.
Here is a photo of a variety called Purple Cherokee. The flesh is sweet, juicy and it is indeed purple-ish in color. Notice that this tomato is huge---one pound and four ounces. There are so many varieties of tomatoes to grow. It's ridiculously limiting to buy the few varieties that your garden center provides. We urge you to plan ahead for next year and try something new.
Now I'm back to the canning, freezing and processing that consumes my day. Happy gardening!