These must be the display device in the Blue Only mode enable.

On professional monitors, a separate button on the front of the display can activate the blue only mode.

The following table shows the different colors in the test pattern, the corresponding code values and the visual impression with activates Blue Only Mode:

If the display is properly adjusted, in the Blue Only Mode the colored areas blend perfectly into the reference areas, without a visible luminance difference.

In Blue Only mode only the blue pixels of a display render the picture on the screen - or, for CRT displays, the blue cathode ray tube.

Also the Blue Only-test image of the company Burosch audio video technology is suitable for use with a blue filter foil or just the Blue Only mode of a display.

In general, all test pattern with a color bar, that includes red, green, blue, and the complementary colors cyan, magenta and yellow can be used to adjust hue and saturation in blue only mode.

The Blue Only Mode is special display mode on display units (projectors, displays, television), in this mode, only the blue pixels, or the blue cathode ray tube is used to generate the image.