It definitely controls the yellow tones. As you can see in the photo, it's exactly that gray! I think you need to bleach at least 3 times to achieve this. I bleached twice and this is the result. Also, if you use it too often, it can look patchy, so I use it about once a week, and I'm satisfied with the color that has a nice grayish tone. Just in case, I wear gloves, but even when rinsing, my nails don't get stained much! The first photo is right after washing my hair, and the second was taken about two days later.