code: func (c *Colorize) ColorPrefix(v string) string {
  	return prefixRe.FindString(strings.TrimSpace(v))
  }
docs: // ColorPrefix returns the first color sequence that exists in this string.
  //
  // For example: "[green]foo" would return "[green]". If no color sequence
  // exists, then "" is returned. This is especially useful when wrapping
  // colored texts to inherit the color of the wrapped text.