A visualisation of paintings in three dimensional RGB space.
Each pixel from a 24-bit colour image of a painting is converted into a set of three coordinates. The coordinates represent the colour information within each of the the red, green and blue channels.
This colourspace mapping may or may not be completely representative of the original painting.
Colour representation and reproducibility is a complex topic, and capturing
the true colour of an object is heavily dependent on imaging conditions, equipment used as well as how the image is ultimately stored digitally.
Paintings themselves are not immune to changes in colour. Pigments can fade or darken over time, while paper and canvas discolour as they age. Varnishes on a painting can also add tints to paintings as they turn yellow or darken. Hence an old painting today can look very different from when it was first painted.