There are 38 colors in the line. Synchromatic is a step down in brilliance from Radiant Concentrated. Most colors in both lines can be intermixed. Spectralite and Hydrus are both made with Fine Art pigments. There is no dye in these products.
Many artists mistake the word ink as a type of colorant.
Yes , each of the colors in both lines are lighfast. There are two basic types of colorants, Pigments and Dyes. However, there are many types of dyes and only a few type of pigments. Dyes can be classified as natural or synthetic. In the Pigments there are the organic and inorganic , natural and synthetic.