  An attribute sequence starts with an escape character, commonly [B^[b],
  although [B^]b], [B^\b] and [B^^b] are also valid. It is followed by one of the
  following letters:

  CCBCA   Bold on
  CCFCA   Flash on
  CCRCA   Reverse on
  CCSCA   Standout on
  CCUCA   Underline on

  CCbCA   Bold off
  CCfCA   Flash off
  CCrCA   Reverse off
  CCsCA   Standout off
  CCuCA   Underline off

  CCaCA   All off

  CCCCA   Colour - see below

  In general, an upper case letter turns on an attribute, and a lower case one
  turns it off. The only exception to this is CCCCA for Colour, which does not
  have a "turn off" attribute and must be followed by a third character which
  signifies the colour.

  Valid colour sequences (after an escape character) are:

  CCCKCA        Black foreground
  CCCRCA        Red foreground
  CCCGCA        Green foreground
  CCCYCA        Yellow foreground
  CCCBCA        Blue foreground
  CCCMCA        Magenta foreground
  CCCCCA        Cyan foreground
  CCCWCA        White foreground
  CCCACA        Default foreground (white)

  CCCkCA        Black background
  CCCrCA        Red background
  CCCgCA        Green background
  CCCyCA        Yellow background
  CCCbCA        Blue background
  CCCmCA        Magenta background
  CCCcCA        Cyan background
  CCCwCA        White background
  CCCaCA        Default background (black)

