Of course this also depends on the kinds of tattoos you specialize in. If darker themes are more you style, then you are going to want darker colors than lighter ones. While many good tattoo kits may include a lot of these things, a good kit will also include a list of good suppliers so you can purchase more without having to search around for them. These definitely have to be wholesale suppliers, and companies that sell supplies in bulk. This is the only way you are going to make any real money, by purchasing quality supplies at the lowest prices possible.