Demi permanent hair color can last up to 6 weeks and typically fades after 20 to 28 hair shampoo washes. As a hair-coloring agent, demi permanent formulas are used to enhance natural hair color, to darken the natural hai... More »

Semi-permanent hair coloring washes out after six to 12 shampooing sessions. It can only darken hair or add a tone of another color to the hair. Semi-permanent hair coloring is ideal for trying out a color change to see ... More »

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Demi-permanent hair color falls between permanent and semi-permanent hair color. Demi-permanent color is less damaging to hair than permanent. "Demi" colors last up to 24 washings, which is longer than "semi" colors; how... More »

Users of semi-permanent or temporary hair color can expect their color to last for about 6 weeks. Color fades with shampooing and exposure to air. More »

For a standard color application, leave Clairol Professional hair color in for 30 minutes, and to completely cover gray, 45 minutes is recommended. During the coloring process, the first 15 minutes the color is on the ha... More »

To remove rust from hair, use a hair color remover, then apply hair dye to get new color. Choose matching hair dye before removing color to get the best match. More »

www.reference.com Beauty & Fashion Hair

Semi-permanent hair color lasts about four weeks or up to 28 shampoos. Permanent hair color lasts until the colored hair grows out, but recoloring is necessary every four to six weeks as the roots grow out. More »