This interactive CIE 1931 Diagram is a Java applet so Java plug-in is required.
Cookies are also required to remember the size of the diagram so you will not need
to resize it the next time you visit this diagram.
The three buttons on the top of the diagram allow you resize the diagram.
If "Show monochromaitc light" is checked, moving the scroll bar below
it will show a dot corresponding to the monochromatic (i.e. single wavelength) light.
Its wavelength is displayed below the scroll bar. Its corresponding X, Y, Z and
R, G, B values are displayed at left uppper corner.
If "Show monochromaitc light" is not checked, the left upper panel will
show the X, Y, Z and R, G, B values corresponding the the point where mouse cursor
CIE chromaticity diagram is a 2-D diagram in a 3-D (xyz) space, so the best way
to present it is to draw it in the 3-D xyz space and allow it to be looked at from
different angle. Biyee has a limted version of 3D CIE 1931 Diagram
(Java 3D needs to be installed).
Since it is impossible for a color monitor with RGB phosphors to display the full
spectrum of colors of a true CIE diagram, the part that has negative R, G, or B
values are displayed by adding white to them untill the most negative value is raised
The following table lists different variants CIE 1931 chromaticity diagram
These diagrams are applets, so it may take a few seconds to draw on a slow computer,
but it is accurate to the limits of the displaying monitor while keeping a small
download file. The problem with using image files for CIE diagrams is that
they are either very large bitmap files or compressed lossy files such as JPEG that
lose some color accuracy. These applets will be available as a downloadable
JavaBeans for plugging into your application soon.
These diagrams are based on 1931 2-degree CIE xyz color matching functions that remain
international standards in both colorimetry and photometry. International
Telecommunication Union uses 1931 CIE color matching functions in their recommendations
for worldwide unified colorimetry (ITU-R
BT.1361). Most color monitors comply with the standard.
This makes it possible to display 1931 CIE diagrams correctly on different color
There are other color coordinate systems most of which are not any kind of
transform of 1931 CIE system, so it is impossible to display diagrams of those system
correctly on different monitors that are calibrated with 1931 CIE system.