Red screen
A solid red screen, dimmable, for dark rooms and red channel checks.
Press Esc to exit
Hex, rgb() or a color name
Presets
Or press 1 to 0 once the tool has focus.
On screen:
Other versions
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Color screen
Pick any color and fill the whole screen, with brightness and an optional clock. -
Black screen
A completely black screen you can put in full screen in one tap. -
White screen
A plain white screen: a soft light source, a light table or a pixel test. -
Green screen
A solid green field for keying tests, subpixel checks and green light. -
Blue screen
A solid blue field for subpixel checks, keying and a calm background. -
Yellow screen
A bright yellow screen for warm light, checks and a strong background. -
Purple screen
A solid purple screen for mood light, backgrounds and colour checks. -
Pink screen
A soft pink screen for gentle light, backdrops and colour tests. -
Orange screen
A warm orange screen for evening light, backdrops and colour checks. -
Gray screen
A neutral gray field for white balance, uniformity and quiet backgrounds.
Related tools
A screen filled with #ff0000, which you can dim to a faint glow. Deep red light lets your eyes stay adapted to the dark far longer than white light does, which is why astronomers, night walkers and darkroom workers use it. Turn the brightness down to 10 or 20 percent, put the phone face up on the table, and you can read a star chart or find a lens cap without losing twenty minutes of adaptation. On a monitor, a solid red field also shows the red subpixels on their own, which makes a failed one easy to spot.
How to use
- Open the page; the screen is already red.
- Drag the brightness down to 10 or 20 percent for use in the dark.
- Press Go fullscreen and turn the clock on if you need the time. Press Esc to come back.
What it handles
- Pure #ff0000, so only the red subpixels light up and the field stays deeply saturated.
- Brightness goes down to 10%, which is dim enough to use next to a telescope.
- The clock overlay turns white on a dim red screen, so the time stays legible without a second light.
FAQ
Does red light really protect night vision?
Largely, yes. The rod cells that give you dark-adapted vision are least sensitive to deep red, so red light disturbs adaptation much less than white or blue light of the same brightness. Brightness matters as much as colour: a glaring red screen will still spoil your night vision.
Can I use this in a darkroom?
For orientation, not for handling paper. A screen emits a broad red that most black-and-white papers tolerate for short moments at low brightness, but it is not a tested safelight. Do a fog test with your own paper before you trust it, and keep the display far from the working area.
Why does a red screen look uneven or grainy?
A fully saturated primary uses only one subpixel of three, so the surface has more visible structure than a white field, especially on low-density panels. Compression in a screenshot adds blotches of its own. Look at the page itself rather than a photo of it before you judge the panel.
Updated