If you only use the chromium dye, it is sort of greenish brown and can get greener with age.
What most folks use chromic dyes for, like Ron Wilson's Magic Maple Stain ( what I use), is to react with the sugars in the curly part. That makes the curl more accessible to the dark stain, which will allow the darker color to go deep into the wood. At each coloring, you sand the wood back to light color, leaving only the color in the curl. Several coats ,even using different colors, may be needed to get the curl the right color and darkness. Sometimes even black dye is applies to get the curl really dark. The final dye color is to stain the light wood as desired.
I saw a stunning handle done in dark red curl and a light green wood a while back.
Aqua Fortis is a great dye, too....but a bit more work.