Abstract

Grossetestes’s treatise on colour, De colore begins with the statement ‘Colour is light embodied in a diaphanous medium’. (The Dimensions of Colour: Robert Grosseteste’s De colore, ed. and trans. Giles E M. Gasper, Hannah Smithson et al). This leads to the question, what might that diaphanous medium be? To the artist working primarily in glass, this is a simple question to answer, it must be glass, (as opposed to air or water). This paper explores Grosseteste’s treatise De colore (On Colour) and discusses how glass and more particularly coloured glass is a perfect medium to demonstrate his theories.