Ardell gray magic color additive helps you cover gray hair completely. Compatible with all color tints toners and no-peroxide hair colors. 10 drops for every ounce of color. Can be used with any hair color additive toner tints and non-peroxide hair color. Will not affect processing time. Contains 30 applications 1.0 oz. Contains 120 applications product options available are as follows: Size: 0.25 oz - Ardell gray magic color additive - cover gray completely size: 1.0 oz - Ardell gray magic color additive - cover gray completely.