1) Look For semi permanent rather than permanent hair color- these use fewer harsh chemicals, which can rough up your hair.
2) Look for ammonia-free(or low ammonia) low -PPD dyes. Ammonia and PPD (p-phenylenediamene) help hair color stick to the hair shaft, but they can be irritating to the skin and dry out hair so use as little as possible.
3) Try vegetable based color or henna. Veggie based color doesn't last as long as conventional color, and it isn't easy to get a subtle look with henna, but they won't damage your hair. Veggie based hair color: Herbatint, Naturtint, Aveda Color Current Energized Gel Color, Light Mountain Natural Henna Hair color.
4) Last but not least if your hair is damaged, wash with shampoo for color- treated hair, use a moisturizing conditioner and give yourself a deep conditioning treatment once a week to help put moisture back into your hair.
Some Products for color treated hair: Paul Mitchell color protect re constructive treatment, L'oreal Vive Hi- Light Boosting Shampoo..