I was going to suggest Color by Robert Craig, but it is semi-permanent and won't lift color either. It can, however, turn those grays into nice, natural-looking highlights if you use a very light shade.
Originally Posted by CurliLocks
This is what I do ... use a lighter brown to turn my greys into nice highlights. BTW, Robert Craig is the ONLY hair color I've used in the past couple of years and I LOVE IT! It's the only color I've used that doesn't demolish my curls for a few days.

And Curlypearl had a great regimen for using protein before coloring.
med/coarse texture; med/high porosity; 3b; iii; 30" long (waist)

CWC using whatever works this week

A curly girl married to a curly guy!