Blue Screen
Pure blue — RGB 0, 0, 255 — drives only the blue sub-pixel. It is the second chroma key standard, a common calibration reference, and the colour where panel weaknesses like banding and uniformity tend to show up first.
What people use the blue screen for
Blue screen keying
Blue is the right key colour whenever the subject wears green, and it was the film industry standard long before green took over for digital. A monitor filled with flat blue gives you a small, even key surface.
Test the blue sub-pixel
Blue sub-pixels are the dimmest of the three and often the first to show defects. Full screen blue makes a dead or stuck blue element easy to find.
Cool mood lighting
A blue-filled display is an instant cool practical light — good for night scenes, gaming setups and moody portrait fill without buying gels.
Check for banding
Flat blue is unforgiving. If you can see stepped bands rather than a single even field, the panel or the connection is limiting colour depth.
How to use the blue screen
- 1Open the blue screen — it fills the page immediately, no button needed.
- 2Press F or use the fullscreen button to go edge to edge with no browser chrome.
- 3Use the brightness slider to dial the output up as a light source or down for a dark room.
- 4Move the mouse or tap once to bring the controls back; they fade out on their own after a few seconds.
- 5Press a number key or use the colour strip to jump straight to another colour.
Frequently asked questions
How do I make the blue screen fill my whole display?+
Press F (or click the fullscreen button) to enter true browser fullscreen, which hides the tab bar, address bar and taskbar. Press Escape to leave. On mobile, tapping the screen hides the controls; add the page to your home screen for a fullscreen launch every time.
What is the exact blue colour used here?+
#0000FF. You can copy it from the control bar, or open the colour picker to dial in any other value and keep it in the URL so the exact shade is bookmarkable.
Does this work on phones and tablets?+
Yes. It works in any modern browser on iOS, Android, Windows, macOS, Linux and ChromeOS. Nothing is installed and nothing needs an account.
Is it free, and are you tracking me?+
Free, with no sign-up. Every tool here runs entirely in your browser — no colour choices, screenshots or usage details are sent anywhere.