Colour code according to the Commission for the Geological Map of the World (CGMW)
This original English version of the International Chronostratigraphic Charter, published in 2022, incorporates colour codes for eons, eras, systems, series and stages.
The charters and more detailed information on GSSPs are available on the website of the International Commission on Stratigraphy (ICS) http://www.stratigraphy.org.
The official Stratigraphic Chart notations are available here: https://ccgm.org/produit/international-chronostratigraphic-chart-with-notations-used-on-geological-maps-pdf/