Aveda Hair Colors

I recently went to an Aveda Concept Salon to have my hair colored. I have grey in the front of my head. The hair technician told me that he gave me a "demi" perm color. This color was from Aveda's professional line. Can anyone tell me what is a demi perm? In reading William's column on hair coloring I did not see this term referenced anywhere.Does Aveda's "demi" perm color have Henna? Is this "bad". The technician also told me that I could have my hair relaxed in a few weeks and not have to worry about the new color getting stripped. Is this true? If I go back I am assuming that would be using Aveda's relaxing product as well (I will definitely check into this).Does anyone have any experience with Aveda's professional line of products?Thanks for any information.