Originally Posted by
rena
Hi Tweety :).
When the cuticles of hair are opened, or in other words, "porous", moisture as well as anything else you want it to retain (such as color) easily escapes. The more alkaline something is, the more porous it will cause your hair to be, but the more acidic something is, the better it will keep the cuticles from raising which will better seal in what you put on it. Hair is at its best when its cuticles are nice and tightly sealed. It shines and holds in moisture.
In answer to your question, conditioners and other products for color treated hair are formulated to be extra acidic in order to help the hair cuticles stay sealed which helps to preserve the color. In doing so, it has an added effect of improving the hair's condition since hair generally likes acidity. Hope this helps ;).