If you feel that you are between 2 colors, we recommend choosing the darker color.
Your hair will not hold onto more pigment than your natural hair structure allows. We recommend choosing the darker shade if you're between colors to provide your hair with enough eumelanin to work with. If you choose the lighter shade, your hair may not receive enough eumelanin and your gray/white hair may not fully change color.
By choosing the darker color, your hair may appear darker than it's natural color to start; however, it will fade to your innate color within about a week.