def to_standard_hex
      color = @value.dup
      color.insert(0, '#') unless color.start_with? '#'

      # Convert shorthand hex to standard hex.
      if color.size == 4
        color.slice!(1, 3).chars { |char| color << char * 2 }
      end
      color
    end
def to_standard_hex
      color = @value.dup
      color.insert(0, '#') unless color.start_with? '#'

      # Convert shorthand hex to standard hex.
      if color.size == 4
        color.slice!(1, 3).chars { |char| color << char * 2 }
      end
      color
    end
Convert the color value to a standard hexadecimal value

 @example
   Color.new('333').send(:to_standard_hex) # => '#333333'

 @return [String]
   the color in standard hexadecimal format

 @api private