The human eye can distinguish about 10 million different colors. The IPC LFI spectra is an attempt to display the standard colors according the Classic RAL System.
RAL is a colour matching system used in Europe that is created and administrated by the German RAL GmbH] (RAL non-profit LLC), which is a subsidiary of the German RAL Institute. In colloquial speech RAL refers to the RAL Classic system, mainly used for varnish and powder coating but nowadays there are reference panels for plastics as well.
The IPC LFI ‘spectra’ show the nearest equivalents of these color standards The shades may vary from actual RAL standards