Blue Screen · #0000FF Press Esc, double-tap, or click to exit

Solid Color Screen

Blue Screen — Fullscreen Pure Blue

A pure, fullscreen blue field that lights only the blue subpixels. (This is a display test color, not the Windows "blue screen of death.") Blue is dim to the eye, which makes it good for spotting bright specks.

What to use a blue screen for

  • Finding dead or stuck blue subpixels
  • Spotting bright non-blue specks against a dim field
  • Judging blue purity and uniformity
  • Part of a full-color dead pixel sweep

How to use it

  1. Click "Go Fullscreen Blue".
  2. Because blue looks dim, bright dots of other colors are easy to catch.
  3. Cycle red, green and blue to cover every subpixel channel.
  4. Send suspects to the Dead Pixel Test to confirm and diagnose.

Not the Windows blue screen

People search for "blue screen" for two very different reasons: the Windows stop-error and a plain blue test field. This is the second one — a deliberate, pure-blue display-test color with no error involved. It lights only the blue subpixels so you can check that channel in isolation.

Why a dim color helps

Blue is the least luminous of the three primaries, so a pure blue field looks relatively dark. Against that dimness, any bright red or green speck from a stuck subpixel stands out sharply, making blue a surprisingly effective background for catching defects of the other two channels as well as dead blue subpixels of its own.

Related color screens & tests

Dead Pixel Test · Red Screen · Green Screen