Check the guides because what kind of armor you have will affect your dye. There have been a lot of disappointed people who mixed dyes to get a certain color, then when they apply it to their armor, it turns out to be another color. For instance, to get my Druid armor white, I just used staight up silver. But it still looks white(ish). So, check your guides and choose wisely.
White dye is too expensive for me now... I just got silver and decided I wanted to see what black looked like and I didn't like it so I went back to silver...
Silver is by far the best looking for Female Ranger 1.5k Druids...