Green screen: a full screen of chroma key green

One tap fills your display with white or any colour. Set brightness, warmth and an auto-exit timer. No flashing.

A green screen is the backdrop used for chroma key: video software removes one colour and puts a picture behind the subject. You normally want a large, evenly lit green sheet, and this page can stand in when you only need a small one, such as a phone or monitor held behind a prop, a quick keying test, or a backdrop for a small product shot. The green here is RGB 0, 177, 64, a mid green often used for keying, so it is neither neon nor dark. Keep your subject well away from the screen, because green light bouncing off the display tints skin and edges. Keep the brightness steady and avoid reflections on the glass. A phone screen is small and its edges give a hard line, so it is only for tiny scenes, not a full-body shot. The page opens on green; press Go full screen, and tap or press Esc to leave. Nothing flashes.

How it works

  1. Pick a colour, brightness and warmth
  2. Press Go full screen
  3. Tap, or press Esc, to leave

What a white screen is for

A white screen fills your whole display with one plain colour, and this page does it in a single tap: press Go full screen and the browser hides its toolbars. People use it as a soft lamp for reading in a dark room, as fill light for a video call or a photo, to check a monitor for stains and dust, to see dead pixels, and to clean a screen so every smudge shows. Held close to a subject, a bright white phone or laptop screen lights a face much more evenly than a bare room bulb. A sheet of tracing paper or thin white cloth over the glass softens it further for a makeshift light box. The colour chips cover white, black, red, green, blue, yellow, orange, pink, purple and gray, and the Custom chip takes any hex code such as #ffcc00.

Brightness, warmth and keeping the screen awake

The brightness slider runs from 10 to 100 percent and dims the colour painted on the page. It is separate from your device brightness, which you still set with the system controls, so for the brightest light turn both up. The warmth slider appears for white. Moving it to the warm side lowers blue, which gives a softer, yellower light that is easier on the eyes at night. Moving it to the cool side lowers red for a bluer tone. This is a simple red and blue balance, not a measured colour temperature in kelvin. While the colour is up, the page asks the browser to keep the screen awake using the Screen Wake Lock feature. Many current browsers support it. Where it is missing, your phone may still dim or lock after its normal timeout, and you will need to change the device setting.

Timer, keys and leaving

Tap or click anywhere to leave. Press Esc to leave from a keyboard. While the colour is up, keys 1 to 9 and 0 switch between the ten colour chips without leaving. The optional Close after timer ends the screen by itself after 1, 5, 10, 30 or 60 minutes, which suits a night light you do not want to leave on. A short hint shows at the start and while the timer runs, then fades so the screen stays plain. The cursor is hidden in full screen. The page never flashes or alternates colours on its own, because rapid flashing can trigger seizures in people with photosensitive epilepsy. Every colour is steady until you change it.

Limits and privacy

Browsers on iPhone often do not allow full screen for a page element. In that case the colour fills the page instead, covering the content, and you still leave with a tap. The address bar may remain visible there. A white screen is a weak light source next to a real lamp, it can leave a faint afterimage on some screens, and very long use of a bright screen drains the battery and, on OLED panels, can contribute to image retention. The colours are drawn by your browser, so they are only as exact as its colour settings, night mode and filters. Your chosen colour, brightness, warmth and timer are saved in this browser so they are there next time. Nothing is uploaded, and the page counts visits with Google Analytics, never what you chose.

Frequently asked questions

What green does this green screen use?

RGB 0, 177, 64, which is #00b140. It is a mid green often used for chroma keying, chosen by this tool rather than set by a standard. Your video software may let you pick this exact colour as the key.

Can I use a phone screen as a green screen backdrop?

For small scenes only. Hold it 30 cm or more behind the subject so green light does not spill onto them, and keep the brightness steady. A bedsheet or paper sheet is better for a full-body shot.

How do I make my whole screen white?

Press Go full screen on this page. The white fills the display and the browser bars hide. Tap anywhere or press Esc to leave. If your browser blocks full screen, the white fills the page instead.

Can a white screen work as a light?

Yes, as a soft light for a short distance. At full brightness it can light a face for a video call or a book held 30 to 60 cm away. It is far weaker than a lamp, so use it for close work, and add some warmth for evening use.

How do I stop my phone dimming or locking on a white screen?

The page requests a screen wake lock while the colour is up, which works on many current browsers. If yours does not support it, raise the Auto-lock or Screen timeout setting in your phone, for example to 5 minutes, before you start.

Does the screen flash or change colour on its own?

No. Each colour stays steady until you change it with the chips or the number keys. There is no strobe or flicker mode, because rapid flashing can trigger seizures in people with photosensitive epilepsy.

How do I set the auto-exit timer?

Choose 1, 5, 10, 30 or 60 minutes under Close after, then press Go full screen. When the time is up the colour closes by itself. Leave it on Off to stay until you tap or press Esc.

Why does full screen not work on my iPhone?

Safari on iPhone usually does not let a page element go full screen. The page then fills the browser window instead, which still hides the content. For a true full screen, use a laptop, an Android phone or a tablet.