Questions & Answers  Does DYEX come in black? Not yet. Black is still being trialed and tested in Japan and when it is perfected it will then be available for distribution. Back to Top Will DYEX harm the dogs' skin? No. It is 100% dog friendly, although it is not recommended for use on dogs with skin conditions or open wounds. Back to Top Does DYEX colour over black coated dogs? No. DYEX does not contain any bleaching agents so it will not colour over black hair. Back to Top How long does the colour last for? DYEX is classified as semi-permanent but it can last longer on some coats more then others. If it takes to the hair well then the dye will fade and grow out over about 6 months. Back to Top Is DYEX safe to use on other animals? Yes. DYEX has been used on cats, guinea pigs and ferrets without any known side effects. Back to Top Does the foil used to wrap the hair in help the DYEX process? No. We simply recommend to use foil as a way of securing the hair in place and keeping it from going onto other parts of the coat. Back to Top