I have never used this product but I used to color my hair all the time. About 10 yrs ago I decided that I would go all natural. My hair is still a bit darker gray in the back but mostly white around my face. I earned this gray hair and I am keeping it. If your company would phase you out because of a hair color maybe you need to get a different job.
It is sad that someone judges your performance by your looks and not your knowledge.