bold
     This style is meant to replace the old option code(-b)code of a2ps 4.3. It is a copy of the black and white prologue, but in which all the fonts are in Bold.

bw
     Style is plain: pure black and white, with standard fonts.

color
     Colors are used to highlight the keywords.

gray
     Gray foreground is used for comments and labels.

gray2
     Black foreground is used for comments and labels.

matrix
     The layout is the same as bw, but alternating gray and white lines. There are two macros defining the behavior: pro.matrix.cycle defines the length of the cycle (number of white and gray lines).  It defaults to 6. pro.matrix.gray defines the number of gray lines.  Default is 3.