Grey helps you to separate your emotions from those of others. A grounding color which helps with your self-esteem. A grey Prism trollbead does much of the same, it grounds bright the bright color Trollbeads.
The Trollbeads Prisms are also available in Kits. The original Prism Kit and the Spring Prism Kit. When you purchase a Kit you are getting 6 beads but only paying for 5.