CIE XYZ color space


The CIE color spaces were the first to quantitatively link the relationship between visible light stimuli and colors perceived by humans.


The CIE RGB color space and CIE XYZ color space were defined by the International Commission on Illumination (CIE) in 1931. These are numbers that are independent of specific devices, etc., and can represent all colors that the average human can perceive.

CIE RGB色空間とCIE XYZ色空間は1931年に国際照明委員会 (CIE)により定義されました。これらは特定のデバイスなどに依存しない数値で、平均的な人間が知覚できる全ての色を表すことができます。

As the name suggests, RGB directly expresses the distribution of the three primary colors, which is more intuitive, but it has the drawback that negative values must be used for the range of colors that could not be reproduced in their experiments, and XYZ was defined to work around this.


X, Y, and Z can be thought of as the magic three primary colors that do not exist in reality but can be mixed to reproduce any color. RGB and XYZ can be linearly transformed into each other.


The demo below draws the XYZ color space as a cube. It is for reference only, as a large range of colors are not representable on a computer display.


Screenshot 2023-02-10 at 4.01.05 PM.png