Colour is highly subjective, but has observable psychological effects, although these can differ from one culture to the next. Black is associated with mourning in the West, but elsewhere white may be. Some painters, theoreticians, writers and scientists, including Goethe, Kandinsky, Isaac Newton, have written their own colour theories. Moreover, the use of language is only a generalization for a colour equivalent. The word "red", for example, can cover a wide range of variations on the pure red of the spectrum. There is not a formalized register of different colours in the way that there is agreement on different notes in music, such as C or C# in music, although the Pantone system is widely used in the printing and design industry for this purpose.