code: @Override
    public void validateColorCode(String code) {
      Preconditions.checkNotEmpty(code, "color code is empty");
      Integer numericColorCode = Integer.valueOf(code);
      boolean isColorCodeValid = numericColorCode > 0 && numericColorCode < 257;
      if (!isColorCodeValid) {
        throw new IllegalArgumentException("color code should be a number between 1 and 256");
      }
    }
docs: Validates terminal color code For reference check website:
  http://misc.flogisoft.com/bash/tip_colors_and_formatting
  
  @param code numeric value as a String