Rainbow Screen

What the rainbow screen shows

The screen runs through every hue from left to right: red, yellow, green, cyan, blue, magenta, and back to red. Every point is at full saturation and medium lightness (HSL hue 0° to 360°, 100% saturation, 50% lightness), so at any point at least one subpixel is fully on and at least one is off. The gradient is still: nothing moves or flashes.

How to use it

1. 1

   Open it full screen. The gradient then spans the whole width of the display.

2. 2

   Turn off color filters. Night mode and blue-light filters shift the blues and greens.

3. 3

   Look for smooth transitions. Each hue should flow into the next. Visible stripes or steps can mean the display or its settings reduce the number of color levels.

4. 4

   Compare displays. If you have a second screen, open the page on both. Differences in how saturated or shifted the hues look are easy to spot side by side.

As a colorful backdrop

A display showing the gradient can serve as a colorful background behind a small object or in a video call. Keep it close, since a screen is a weak light source, and light your face with a neutral light so the colors fall only on the background. Lower the display's brightness if the colors look too strong on camera.

Limits

The rainbow covers the hues a display can mix from its red, green, and blue subpixels, not every color in the visible spectrum. Exact shades depend on the panel and its settings. For a detailed check of smooth gradients, use the Color Banding / Gradient Test; for single colors, start with the Red Screen; for comparing colors, the Color Accuracy Test.