Ends too dark, can it be fixed?

Hi I'm new and hope someone can help me. Quick history, natural hair is mousie light brown with red tones. Very dull. I used med. ash blonde got a med auburn. After roots grew out used light ash blonde got a lighter auburn.

Roots grew out and this time I wanted a darker red. Hair is permed. I tried Herbal Ess. true red. It came out very purpley. Called the hotline, they suggested mix half developer and colorant with 1 oz shampoo and recolor with Nice and easy 117 Nat. Med. golden brown to tone it down. The roots are just what I wanted, a dark auburn red. The ends are a dark ashy brown, almost charcoal color. I guess my ends were not in that good a shape. Is it fixable?

Hard to get a picture, it doesn't look as dull in the picture as it really is.