Colour paste
A colour paste is a pigment paste, which can impart a transparent or opaque colour to resin. For example, a quantity of polyurethane colour paste can be added to a casting resin to give the resin the desired colour. Polyurethane colour pastes are known for their strong colouring power. For more info, see; https://www.v-sure.eu/en/products/ancillaries/pigments-dyes/