I can't answer yet to this question. All experiments I have done until now, show that hair dye containing PPD or PPD-derivatives is a very weak color developer, you need almost to bypass bleach to get a negative that contains some vestiges of color. These colors may be then «developed» with a software like GIMP.
But I am still trying to achieve better results. It is sometimes disappointing, and if you don't take notes of all details, it may give a satisfactory result that you can't reproduce again, maybe it was another film brand, maybe the new bottle of soluble coffee is different or something else that you can't explain. By the way, I already explained why I am using coffee in some earlier post. In one of my first experiments with color negative film, I tried B&W reversal cross-process and with help of software I could extract some color. On the other hand coffee is acid and helps you to adjust the pH of the developing bath.
One of my last failures with hair dye gave monochromatic pictures like this: