I was so excited to grow these San Marzano tomatoes from seed, and have actually been thrilled with the results while they were growing(they are gorgeous!). However, they are growing in a partially shaded site (which didn't seem to be a problem), because they have just been so prolific. But I am having a hard time getting them to turn red, and when they are done- they are disappointingly lightweight and pale.

My other tomatoes are fine, but I was so hopeful for these!

The plant itself looks great and healthy (actually almost 9 feet tall and LOADED with fruit). It's just the end result that is the problem.

Any ideas what the problem is? I'd like to try them again next year successfully. Thanks!