We have a row of five camellia bushes at our new house, although "bushes" is a stretch -- tree is more like it. The biggest is taller than our neighbor's two-story house and quite broad as well.

I think they are all camellia japonica, as the flower forms are all similar. The pink ones bloomed first this year, followed by white and then a dark red.

Now that the blooming is wrapping up, I'm beginning to see issues with the pink ones (they are the farthest along). The leaves are uniformly turning a lighter green, and a few random ones throughout have yellow splotches followed by brown dead spots starting from the stem end and spreading before the leaf drops. Is it normal for the tree to turn lighter green after blooming? The pink ones are not next to each other but are going through the same process. And what could cause the leaves to drop?