Interaction of colour - Colour is relative

I've spent a good few hours looking at, reading and admiring the contents of a slip-cased limited edition, of 'Interaction of colour' by Josef Albers, complete with the full range of screen printed plates to accompany his text. Albers writings demonstrate principles such as color relativity, intensity, and temperature; vibrating and vanishing boundaries; and the illusion of transparency and reversed grounds.

Colour relatively 

A colour can appear to change depending upon the other colours around it.

The following examples illustrate how the same colour can be made to look different.