One tap fills your display with white or any colour. Set brightness, warmth and an auto-exit timer. No flashing.
Search for a blue screen and you may be looking for a plain blue display, not the error screen of an operating system. This page gives you the plain one: pure blue, RGB 0, 0, 255, across the whole display. It is useful for checking the blue channel of a monitor or phone, since a dead or stuck blue sub-pixel shows up as a dark or off-colour dot on a pure blue field. Video makers also use it as a plain backdrop, and some people want it as a mood colour on a spare screen. It opens already set to blue; press Go full screen, then tap or press Esc to leave. Use the number keys to move to other colours without leaving. Be aware that blue light is the part of a display's output most often reduced by night modes, so if your device has one switched on, the blue may look dull or purple. Turn night mode off while testing. This page cannot repair a faulty pixel.
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.
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.
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.
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.
No. This is a plain blue colour for lighting and display checks. It cannot fix, simulate or diagnose a crash, and it does nothing to your computer except paint pure blue, #0000ff, in the browser.
Night mode, True Tone or a colour filter often lowers blue to warm the screen. Switch it off in system settings and reload. Also check that browser brightness on this page is at 100 percent.
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.
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.
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.
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.
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.
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.