I had a difficult time finding the shade I wanted (light golden brown) a few years ago. They seemed to only offer medium brown and darker (level 5) or blonde (level 8). Their work around was to mix two different dyes in one developer bottle to get the shade I wanted. It worked but then I had to order two kits at a time to get both tubes of color.
OP-What are you trying to achieve with hair color? Lighter, darker, just something different, gray coverage, save money?