You can send a strand of your hair with an enclosed self addressed stamped envelope(so they can mail it back to you)to Ecocolors Salon strand test Dept. 1860 n rock springs Rd #101 Atlanta GA 30324 Be sure to tell them what color you would like to try(medium brown, dark brown, etc. and the % of gray on your head..and if you have any other chemicals in your hair..color,bleach or perm)