Stelara and hair dye

This may be a strange question, but I am wondring if anyone else on Stelara (Ustekinumab) also dyes their hair? I am not concerned from a scalp psoriasis angle, but I am finding that the hair dye just isn't holding. Although the hairdresser is using permanant hair colour, my hair is behaving as if it is semi-permanant. After 6 weeks, most of the colour has been stipped out. I am using the correct shampoo and conditioner for coloured hair. I was just wondering if the Stelara was somehow affecting the hair making it unresponsive to colouring.