Chances are you saved up for the color of your dreams and spent hours sitting in the salon and you have finally made it! Now how long will it last?
The farther away from your natural color you go the faster you will see the roots growing out. Often the following day from going platinum blonde you will see your dark roots already visible 24 hours later. With white hair ( grey ) that you are coloring you will see them the same way in 24 hours. Hair is continuously growing so the roots will appear no matter what you do.
The closer to your natural color you keep it in depth and tone the less Maintainence you will have.
Always discuss your ideal hair color with your hairstylist so there is no surprises.