public static function Color2Hex( $colorDefinition )
   {

      if ( \is_array( $colorDefinition ) )
      {
         if ( \count( $colorDefinition ) != 3 )
         {
            throw new ArgumentError(
               'colorDefinition',
               $colorDefinition,
               'Drawing',
               'A rgb array with 3 Elements is required!'
            );
         }
         return static::Rgb2Hex( $colorDefinition );
      }

      if ( static::IsHexFormat( $colorDefinition ) )
      {
         return $colorDefinition;
      }

      $uc = \strtolower( $colorDefinition );

      if ( isset( static::$ColornameHex[ $uc ] ) )
      {
         return \strtolower( static::$ColornameHex[ $uc ] );
      }

      if ( false !== ( $hex = static::Rgb2Hex( $colorDefinition ) ) )
      {
         return $hex;
      }

      return false;

   }