Yellow Screen Test

Pure yellow (#FFFF00) full-screen display for blue sub-pixel detection, red+green channel testing, and display color uniformity checks.

Or press F11 · Mobile: double-tap

Brightness100%
10%70–85% recommended for video calls100%

How to Use

1Enter fullscreen mode for maximum screen coverage.
2Check for any color variation across the screen — yellow should be perfectly uniform.
3Look for blue dots (stuck blue sub-pixel) or black spots (dead pixels).
4Yellow = red + green channels active. Any visible blue dot indicates a stuck blue sub-pixel.

Why Yellow Reveals Blue Stuck Pixels

Yellow is a secondary color made by combining the red and green sub-pixels at full brightness while keeping the blue sub-pixel completely off. This makes the yellow screen uniquely effective at exposing stuck blue sub-pixels — any pixel where the blue sub-pixel is permanently stuck ON will appear as a blue or cyan dot against the yellow background. It's the best test for isolating blue channel failures.

Yellow in Display Calibration

Yellow is a critical reference color for display calibration. In the sRGB color space, pure yellow (#FFFF00) is a standard test point. If your yellow appears too green, your green channel gain is too high relative to red. If it looks too orange or warm, the red channel dominates. A perfectly calibrated display produces a clean, equal-intensity yellow with no visible tint shift across the screen.

Secondary Color Pixel Testing: The Full Set

The three secondary colors (yellow, cyan, magenta) are the counterparts to the three primary colors (red, green, blue). Each secondary color turns off one primary channel, making it the ideal background for detecting stuck pixels in that channel. Running all six colors gives you a complete sub-pixel health report:

Red screen

Stuck green or blue sub-pixels

Green screen

Stuck red or blue sub-pixels

Blue screen

Stuck red or green sub-pixels

Yellow screen

Stuck blue sub-pixels

Cyan screen

Stuck red sub-pixels

Magenta screen

Stuck green sub-pixels

Frequently Asked Questions

What does a yellow screen test detect?

A yellow screen test is specifically designed to detect stuck blue sub-pixels. Because yellow = red + green (with blue turned off), any pixel where the blue sub-pixel is stuck ON will appear as a noticeable blue or cyan dot against the yellow background. It also reveals dead pixels as black dots and tests overall red + green channel uniformity.

Why does my yellow screen look greenish?

A greenish tint on a yellow screen means your green channel is overdriving relative to red. The red and green channels should be equal intensity to produce pure yellow. Check your monitor's color temperature settings and RGB gain balance in the OSD menu. Resetting to factory defaults often fixes minor tint issues.

How many colors should I use to test my monitor?

For a thorough monitor test, run at least 6 colors: white, black, red, green, blue, and one secondary color (yellow, cyan, or magenta). White catches all dead pixels at once, black reveals backlight bleed, the primaries test individual channels, and secondary colors expose stuck pixels in specific sub-channels. Our All Colors page lets you cycle through all 8.