Color Screen — Fullscreen Color Tester, Lamp & Dead Pixel Check

Turn your whole screen any color: white, black, green, red or any hex. Drag to change it, dim it, add a clock, cycle colors. Free, runs in your browser.

What it does

Color Screen fills your display with one solid color, edge to edge. Pick white, black, green, red, any of 140+ named colors, or type a hex, rgb() or hsl() value, then press Go fullscreen. People use it as a clean white or black screen, a desk lamp or fill light, a green-screen reference, an ambient mood glow, or a quick check for dead pixels and uneven backlight.

Beyond a single color it also does a two-color gradient, a timed color cycle, a smooth rainbow sweep, and a five-step display test. A dimmer, an optional clock and a “keep the screen awake” switch make it practical as a lamp or a bedside light.

How it works

Everything is one web page element that the browser’s Fullscreen API expands to cover the whole display. The color is a plain CSS background, so there is nothing to render, download or process.

Color input. Whatever you type is parsed locally: #f80, ff8800, rgb(255, 136, 0), hsl(32, 100%, 50%) or a name such as salmon. Unreadable input is flagged and ignored rather than guessed at.
Drag to change the color. Drag left or right to shift the hue; drag up or down to change brightness (or saturation — your choice). Each gesture locks to the axis you start moving along, so a diagonal wobble doesn’t muddy the color. On white, black or grey, hue dragging switches to a vivid color so you can see the change.
Dimmer. A black layer on top of the color at 0–100% opacity, so a white screen can be turned down to a soft night light without changing the underlying color.
Stay awake. Uses the browser’s Screen Wake Lock feature where it is supported, and re-requests it when you switch back to the tab.
Share links. Copy share link produces a URL that reopens exactly this color, mode, dimmer and clock setting.

Pure “green” here is #00ff00, the bright screen green. CSS’s own green keyword is a darker #008000; type that hex if you need it.

How to use it

Choose a quick color, search the named list, or type a value into the color box.
Pick a mode: solid, color cycle, rainbow sweep, gradient or display test.
Press Go fullscreen (or press F, or double-click the color).
Drag, use the arrow keys or scroll to adjust. The controls fade after two seconds; move the mouse or tap to bring them back.
Press Esc to leave fullscreen. Your last settings are remembered next time.

Keyboard and gestures

F fullscreen · Esc exit · Space pause or next · ← → hue (or previous/next) · ↑ ↓ brightness · − / = dim · C clock · scroll wheel adjusts in fullscreen.

Modes

Solid color: one color, with drag, keyboard and wheel adjustment, plus WCAG contrast readouts for white and black text.
Color cycle: your own list of up to 24 colors, 0.5–60 seconds each, with optional fade. Load it from your saved favorites.
Rainbow sweep: a continuous hue loop from 2 to 120 seconds.
Two-color gradient: any two colors at any angle. If you want the CSS for a gradient you’ve designed, the CSS gradient picker generates it.
Display test: white, black, red, green and blue in turn, for spotting dead or stuck pixels and uneven backlighting. For keyboards, mice and other hardware, Device Testers covers the rest.

Ready-made color pages

For the most common searches there is a page opened straight to that color: white screen, black screen, green screen, red screen, blue screen, yellow screen, orange screen, pink screen, purple screen and grey screen. They all use the same tool; each page explains what that color is good for.

If you only want to stop your screen from sleeping, with no color involved, the Stay Awake tool does just that. To grab a color from a photo first, use the color picker and paste the hex here.

FAQ

How do I make my screen a solid color in fullscreen?

Pick a color, then press Go fullscreen or the F key. Press Esc to return. If your browser blocks fullscreen inside an embedded frame, the color fills the frame instead; open the tool on its own page for true fullscreen.

Can I use any color, not just the named ones?

Yes. Type any hex (#1a2b3c), rgb() or hsl() value, use the color picker, or drag on the screen. You can also pick a color from anywhere on your display with Pick from screen in browsers that support the EyeDropper feature.

Does the screen stay on?

Tick Keep the screen awake. It works in browsers that support the Screen Wake Lock feature. Where it doesn’t, the tool says so and your device’s normal sleep settings apply.

Is it good for finding dead pixels?

It helps. Cycle through white, black, red, green and blue (the Display test mode) and look for specks that stay the wrong color. It’s a quick visual check, not a diagnostic; some defects only show in certain colors or at certain brightness.

Does a bright color screen work as a light?

As a soft fill or night light, yes. It isn’t a substitute for a proper lamp, and the maximum brightness is set by your device. Use the dimmer for a gentler glow.

Can I send someone a link to a particular color?

Copy share link gives a URL that reopens the same color or mode, dimmer and clock setting. The link contains only those settings.

Privacy

Nothing leaves your browser. There are no uploads, no accounts and no network requests while you use the tool, and no external libraries to download. Your last-used settings and favorite colors are saved in your browser’s own storage on your device and can be cleared with Reset settings and Clear favorites.

Limitations

Fullscreen and screen-wake support depends on your browser; iPhones, for example, don’t offer element fullscreen, in which case the color fills the frame. Drag adjustment works in solid and gradient modes only. Display tests can’t replace a manufacturer’s diagnostic.