Curly coloured hair issues!

[Locomom]

I have curly naturally curly hair. I’m 40 and it’s going grey. I’m not ready to embrace grey so for the mean time I colour.
i can’t afford to have it coloured by the hairdresser every 6 weeks nor would I ever have the time, so I do it myself at home. I use garnier nutrisse semi permanent as I think it blends better when fading out, I’d hate white roots given my hair is a very dark almost black/brown.
I find the colour doesn’t last very well 3 weeks and it’s silver again, so I need a colour care shampoo that will increase the time between colours, but also one that will care for my curls, preferably sulphate free. Please suggest something I can try?

No answers for you, as I am in similar position. I had it coloured at Salon in Dec thinking it would last long, but it faded a lot and I had to cover grey three times already.
I use root touch up to cover grey rather than full head now.
I was looking at E salon yesterday, at some point there were lots of good reviews, I was wondering if it would last longer than boxes

What is e salon? Is it just not another brand of at home hair dye? I bought a permanent version of my usual by mistake one time and thought oh happy accident! And although it didn’t wash out as such, somehow the roots were more noticeable, and my hair was definitely in poorer condition.