If you're wondering whether you should use 20 or 30 developer bleach, the answer is that it depends on what you're trying to achieve. 20 developer bleach is typically used for removing color from hair, while 30 developer bleach is used for lightening hair. So, if you're looking to remove color from your hair, 20 developer bleach is the way to go. However, if you're looking to lighten your hair, you'll need to use 30 developer bleach.