Mix equal parts Golden Blonde and Reddish Brown with equal parts developer. Always do an allergy test and strand test according to kit directions. How to apply to gray: Mix equal parts color to developer and apply this full strength mixture to roots only if you have previously colored ends. Process the roots for 45 minutes. For resistant gray, leave the color mixture on the grays for 45 minutes with plastic cap and heat for the first 5 minutes with a blow dryer. Whatever color you do not mix with developer may be saved for the following month's application or stored for up to a year. Once you mix color and developer, you must use it immediately.