# Matches an ANSI 3 or 4-bit color
\e # An Escape
\[ # Followed by a bracket
(?<Color>(?>
  (?<IsBright>1)?\;{0,1}(?<IsForegroundColor>3)  |
  (?<IsBright>(?<IsForegroundColor>9))  |
  (?<IsBright>1)?\;{0,1}(?<IsBackgroundColor>4)  |
  (?<IsBright>(?<IsBackgroundColor>10)))(?<ColorNumber>[0-7])m)