The Chrominance of Spicules is the comparison test which is according to Natural Colour System® (NCS) standard.
NCS - Natural Colour System® is a international scientifically based colour system that allows for accurate cross-industrial colour communication for designers and manufacturers and customers. The system allows you to describe colour on all imaginable surface. This has made the colour system a global standard for definition, quality assurance and communication of colour.
The Comparison Test of Spongilla Spicule Chromaticity