How this test works
Cycle through primary colors and channel ramps to spot clipping, tint, and subpixel problems.
- Prepare the display using the checklist below.
- Select Start test and allow fullscreen mode if your browser asks.
- Use the arrow keys, on-screen controls, or click the pattern to move through the test.
- Exit the runner and save a local observation if useful.
Before you begin
- Disable color filters and night light
- Use a neutral picture mode
- Set browser zoom to 100%
What to look for
- Missing or uneven color channels
- Abrupt changes between saturation steps
- Persistent pixels on solid RGB fields
Important: This is a visual channel check and does not measure chromaticity, gamut coverage, or color accuracy.
Frequently asked questions
What does the RGB test show?
It displays primary color fields and ramps that can reveal obvious channel, clipping, or pixel issues.
Can it diagnose a cable problem?
A missing channel can have several causes, including the signal path, but this page cannot identify the exact cause.
Are the colors calibrated?
The CSS values are defined, but their physical appearance depends on the complete color-managed display path.