Hepatica leaves are very interesting to me. The shapes and the colors can be different with each species, even with each plant, and some of them have both spring and fall colors just like deciduous trees. The photo above was taken in early July and I was wondering what caused this color. Usually I see leaf color changes in the fall when the temperature gets cold but this was happening in the summer. I wonder whether the dry summer heat summer stressed the plant and caused this. I have had this plant growing for several years in this location and I have never seen this happen until this year. I will have to keep my eye on it next year as well.
>> UPDATE <<
It looks like the leaves can change color due to environmental factors. An increase in stress (drought or sun exposure) can cause these symptoms. When I potted up this plant and kept it in a better location and well-hydrated, the leaves remained green though the summer. The new leaves and fall leaves of hepatica can change color but it can happen when the plants are a bit stressed out as well.