UsefulTab
Color Test
Fill the screen with solid colors and gradients to check color output.
Test your screen colors
Color Test fills your display with pure colors and smooth ramps so you can judge how your screen reproduces color. Solid red, green, and blue show each primary at full strength; cyan, magenta, and yellow test the secondaries; white and black set the brightness extremes. The gradient and grayscale ramps are the key accuracy checks: a good panel shows a perfectly smooth fade, while visible steps or stripes ("banding") reveal limited color depth or aggressive processing. A grayscale ramp that stays neutral from black to white indicates a well-calibrated screen; a color tint across it points to a white-balance issue. Press Fullscreen for an edge-to-edge check and click or press a key to cycle. Everything runs in your browser and nothing is uploaded.
Common questions
What is color banding?
Banding is visible steps or stripes in what should be a smooth gradient. It appears when a display (or its settings) cannot render enough distinct shades. The gradient fills here make banding easy to see on an affected screen.
How do I check color accuracy?
Look at the grayscale ramp: it should go from black to white with no color tint. A red, green, or blue cast across the grays means the white balance is off. The solid primaries should also look pure and vivid, not washed out or shifted.
What do the solid colors test?
Each solid fill lets you judge a single color across the whole panel at once — useful for spotting uniformity problems, tint, or clouding, and for making stuck sub-pixels of that color stand out.
How do I run it full-screen?
Press Fullscreen to fill the entire display, then click or press any key to move through the colors and ramps. Press Escape to exit fullscreen.
Is anything uploaded?
No. All colors and gradients are drawn locally by your browser. Nothing about your screen or the test is stored or sent anywhere.