"Color" in the name "color-glass condensate" refers to a type of charge that quarks and gluons carry as a result of the strong nuclear force. The word " glass " is borrowed from the term for silica and other materials that are disordered and act like solids on short time scales but liquids on long time scales. In the CGC phase, the gluons themselves are disordered and do not change their positions rapidly. "Condensate" means that the gluons have a very high density.