Start with white and black, then red, green, and blue. White exposes dead pixels; black exposes stuck pixels; primaries isolate which sub-pixel channel failed.
No single color catches every fault. A structured five-color pass takes about two minutes and finds more issues than white alone.
Color reference
| 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 this order works
White first — fastest scan for completely dead dots. Any fixed black speck on pure white is worth a second look.
Black second — stuck pixels ignore the off state and appear as red, green, blue, or white pinpoints.
RGB third — isolates channel faults. A dot that appears only on the blue screen usually implicates the red and green sub-pixels.
Grey last — not for dead pixels, but for gradient banding that can look like uneven brightness during color checks.
Optional secondary fields
Yellow, cyan, and magenta-style combinations stress two channels at once. Use them to confirm a defect first seen on a primary.
Practical timing
- Allow at least 30 seconds per color in a dim room
- Stay in fullscreen — browser chrome does not count as tested area
- Run two passes when you are deciding on a return or RMA
Automating the rotation
Manual switching is fine. The display tests pixel cycle advances white → black → RGB on a timer so you can focus on scanning the glass.
FAQ
Can dust look like a dead pixel? Yes. Clean the panel, retest, and see whether the spot moves or disappears.
Do OLED phones need different colors? Use the same sequence; also watch near-black grey for uneven pixel glow.
Is one bad pixel a fail? Policies vary by brand. Document with photos on the color that shows the fault most clearly.
Next: Step-by-step dead pixel test · Fullscreen testing setup
