I've used Tesco & Almat Colour powders with no problems & they perform exactly the same as Ariel colour, but usually I just use any detergent of my choice which isn't normally a colour variant. I haven't tried Persil colour but Ariel colour works well & has a gorgeous scent when I decide to use it.
The detergents I have used recently include the new Classic Surf, Persil Bio Powder, Ariel Pods, Ariel Excel Gel & Persil Small & Mighty & none of my items have faded dramatically, even black items have very slight fading but I find if you're using Bio powder then use a slightly lesser dose as this helps to prevent colour fade.
I've never tried any own brand other colour detergents apart from Tesco & Almat but I never usually buy shops own anyway, I just can't bring myself to buy it.