Short answer: Start with white and black, then red, green, and blue. White finds dead pixels; black finds stuck ones; primaries isolate which sub-pixel channel failed.
There is no single “magic” test color. A five-color pass takes about two minutes and catches far more issues than white alone.
Color cheat sheet
| Test color | What fails | Tool |
|---|---|---|
| White | Pixels that stay off | White screen |
| Black | Pixels that stay on | Black screen |
| Red | Weak green/blue sub-pixels | Red screen |
| Green | Weak red/blue sub-pixels | Green screen |
| Blue | Weak red/green sub-pixels | Blue screen |
| 50% grey | Banding and uniformity | Grey screen |
Why the order matters
White first — fastest scan for completely dead dots. Any black speck on pure white is suspicious.
Black second — stuck pixels ignore the “off” signal. They pop as red, green, blue, or white pinpoints.
RGB third — narrows a tint to a specific channel. If a dot only appears on the blue screen, red and green sub-pixels are the likely culprits.
Grey last — not for dead pixels, but for gradient banding that can mimic uneven brightness during color tests.
Optional secondary colors
Yellow, cyan, and magenta-style combinations stress two channels at once. Use them to double-check a defect you spotted on a primary color.
Practical timing
- 30 seconds minimum per color in a dim room
- Fullscreen always — browser chrome untested areas do not count
- Two passes if you are deciding on a warranty return
Automate the rotation
Manual switching works, but the display tests pixel cycle handles white → black → RGB every five seconds. Tap the screen to skip ahead if you see something.
Quick FAQ
Can dust look like a dead pixel? Yes. Clean the panel, retest, and see if the spot moves or disappears.
Do OLED phones need different colors? Same sequence; also watch near-black grey for uneven pixel glow.
Is one bad pixel a fail? Policies vary. Document with photos on the color that best shows the fault.
Next read: Step-by-step dead pixel test · Fullscreen testing setup