Are you sure that you have lilacs? They are not known to be happy in the longs months of zone 8 heat and humidity.

Definitely a lilac. Fairly good sized one, too. We moved in this past Fall before she had dropped all of her leaves and aside from some vines that the previous tenants allowed to grow out of control, she seemed pretty healthy. However, the blooms were long gone so I'm not real sure how they'll react to the heat.

To answer your original question, there is no way to tell the color of a lilac when it's not blooming.

BTW, it's not the flowers that are particularly sensitive to the heat....it's the entire plant that suffers from it, as well as the lack of enough cold weather. I lived in the coastal area for over 20 years and don't think I ever saw a lilac.

Do you mind letting me know where you're located? I'm curious. You can email me directly, if you like.

Miss Kim is one lilac that survives heat and humidity like we have in NC. I don't like it that much, though.