What is the difference between RAL Classic and RAL Design?

The difference between RAL Classic and RAL Design ranges is in the type of the colours and also the amount of  colours.

RAL Classic is a collection of 216 industrial colours developed to meet industry requirements. Typically the colour of bridges or buildings and equipment for industrial applications as well as aeroplanes and trains are specified in Classic colours. The RAL Classic colours are often used to specify paint and powder coated items as well as resins e.g. window frames and garage doors. In order to be in this collection the colour must be of non-business specific interest and not be subject to fashion trends.

Did you know that the golden yellow of the German flag is RAL 1021 and that ICE trains are RAL 7035?

RAL Design is a colour system containing 1825 colours following the internationally recognised CIELab system. RAL Design colour codes have seven digits whereas RAL Classic colour codes only have four digits. The Design colour range contains more subtle colours than the Classic range, developed for architects and interior designers. It is intended to provide a comprehensive range of colours for interior and decorative design. The RAL Design system colours are also used in the RAL colour books which are used for reference, education and inspiration. RAL colour books are available for interior design of hotels and healthcare settings such as hospitals and clinics as well as domestic homes.