The Magic Circle Spells 2:

Now many of you whom think you know it all may want to write me and tell me that they have to be certain colors and so forth, I say Bullshit. What I am telling you comes from trial and error. That is Experience. A Magic circle can be drawn in the sand or carved in concrete or painted on fabric. If they are painted on a surface they are usually in Black and White. All these methods of using a Magic Circle have worked for many famous Magicians/Sorcerers for decades. If Aleister Crowley were alive today he would tell you the same.

Below are some of the Famous Magic Circles that have been used throughout time. There are others that can be found in different Grimoires, but these are enough to give you an idea of how they differ from each other and their similarities.