Demi Color Application: Developer Strength & Filler Use

Question
My hair is a spicey red. I want to do a red now maybe a crimson red! My guestion is should I use a red filler along with the Demi color? Also what strength developer do I need? 20?

Answer
Tanya,
 Demi colors usually have dedicated developers specific to the product or will specify what is meant to be used in their directions. Most demis do not need filling in advance. Also, since they are meant to be deposit only, you'll want to make sure that the color you use is the same level or darker than what is currently on your hair or it will not cover. If your hair is darker than the color yopu will be using it will have to be lifted a bit before applying the new color.
Best of luck to you.
Stephe (hairman)