... Consider engaging color and color care products which offer the ultimate ability to banish unwanted warmth. Expand your color choices from violet. Select BLUE. Why? Because blue is the coolest color -- cooler than violet ( which contains red), able to minimize or cancel unwanted red, orange or gold hues our clients describe as being 'Brassy'.
When I am covering gray hair as I also plan to create cool brown or cool blonde results, I enjoy great success mixing equal parts of a blue/based and a neutral based shade at the same or similar level; thereby creating a 'cool neutral'. - great coverage of gray, AND a supply of cool tone which eliminates undesirable warmth in the hair.
And, at the shampoo bowl-- you can continue your efforts maintaining 'never brassy' hair color, --,consider using a blue color care shampoo when washing both blonde and brunette clients. This works so well on my clients. Let me know if you are enjoying this as well! B