Demipermanent Hair Color Much like its close cousin, semipermanent hair color, demipermanent color creates a more natural looking effect without lifting any levels or tones out of the hair. However, a demi will last much long, usually between 20 to 28 shampoos. And because this type of hair color gently fades out with each washing, there are no noticeable roots. Demipermanent color is considered gentle and ammonia-free, using a low level of peroxide to penetrate the hair shaft. This means the chemicals work to deposit color, providing intensified, deepening results.