Question about salon and hair dye?

I have dark brown dyed hair, naturally dark blonde hair. My brown is always very reddy, brassy toned especially in the sun or when my hair fades. Whenever I go to the salon and ask them to JUST darken my blonde roots, they always go way to far down and darken everything BUT my roots. And when they do dye my roots... show more I have dark brown dyed hair, naturally dark blonde hair. My brown is always very reddy, brassy toned especially in the sun or when my hair fades. Whenever I go to the salon and ask them to JUST darken my blonde roots, they always go way to far down and darken everything BUT my roots. And when they do dye my roots it's always a reddish blonde color. Which they usually are surprised by and have to redo them. And when I ask if they can fix te reddish brown and go for more of a neutral ashy brown (not green or dull, but not red either... iv seen many girls with this basic brown hair and that's what I want, ashy, light or dark.) they always say they have to lighten my hair in order to get the red out and make it an ashier brown. I don't want to damage and bleach my hair. Is there any way for them to just tone the red in my hair or put a dye over it to correct the color without making it darker? I don't want pitch black but like a very light black or a very dark ashy brown.