The top-rated hair dye is Clairol Natural Instincts in brown or red tones, according to Good Housekeeping. L'Oréal ColorSpa Moisture Actif in chestnut reddish brown is also recommended.
The website cited the Clairol product's even coverage, shine and fade resistance in making its top choice. The L'Oreal product provided gray coverage and shine, but did not cover gray hair as well. The best color for brunette hair was Revlon ColorSilk in dark brown, which covered gray hair completely, according to test results. The dyed hair retained its shine, didn't fade and was the least expensive of the dye kits tested.
The test for best hair color for blond hair resulted in a tie between Clairol Nice 'n Easy in Natural Dark Neutral Blonde and ColorSilk in Ultra Light Natural Blond. The researchers were impressed by the product's fade resistance and shine retention. ColorSilk in Burgundy was the best-tested product for redheads, doing well in both grey coverage and shine. As with most red color shades, the product had some color loss after four weeks of washing and drying.
The website tested nine best-selling formulas that claimed to cover gray hair without fading. The researchers dyed swatches of gray hair, then washed and blow-dried the samples and exposed them to ultraviolet light to simulate normal wear over the course of a month.