The squamous epithelium of the cervical portio is similar to that of the vagina, except that it is generally smooth and lacks rete pegs. Colposcopically, it appears featureless except for a fine network of vessels which is sometimes visible. The relative opacity and pale pink coloration of the squamous epithelium derives from its multi-layered histology and the location of its supporting vessels below the basement membrane. [ http://www.asccp.org/practicemanagement/cervix/histologyofthenormalcervix/tabid/5842/default.aspx ]