How to check full-screen color patterns on a TV

A TV can show a sharp desktop and still hide a problem until you look at a full-screen color. A colored pixel, uneven tint or cut-off edge may be easier to spot on a plain pattern than on a busy picture.

Use the Display Test to inspect colors on the TV. If your computer has more than one display, the Screens test can help you target the TV's display. The results can reveal visible issues, but they cannot calibrate the TV or prove that its panel is perfect.

Show color patterns on the TV

1. Connect the TV to your computer, usually with an HDMI cable, and set it to the computer's input. Open the Display Test.
2. If the test is on the wrong display, open Screens and use its color test on the TV. Check the display name or resolution first so you know which screen you are testing.
3. Make the pattern fill the TV. Use the browser's full-screen command if needed, then use the test's color patterns. Look at the screen from a normal viewing distance, and move closer only to inspect a suspected pixel.
4. Check several available colors, including a light color and a dark one. Look for dots that stay the same color, uneven patches, tinted areas, and image edges that appear cut off.
5. Repeat the check after changing the TV's picture or display settings. Change one setting at a time so you can tell what affected the result.

For a fair check, let the TV warm up for a few minutes and view it from directly in front. Clean visible dust from the screen gently before treating a speck as a pixel defect.

What the pattern shows

The color fills the screen evenly

No obvious defect appeared on the colors you checked. This does not guarantee that every pixel or every shade is perfect. A fault may show only on a particular color, brightness level or screen position, so cycle through the test's available patterns.

A dot stays dark or keeps one color

A dot that remains black on bright patterns may be a dead pixel. A dot that stays red, green, blue or another color may be stuck. Check it on more than one pattern and at normal brightness. Dust on the screen can look similar, but it may shift or disappear when the screen is cleaned.

One area looks tinted, dim or blotchy

This may be uneven panel illumination or a picture setting, not a single bad pixel. Compare the same area across light and dark patterns. If the patch changes with the picture mode, backlight, local dimming or viewing angle, the TV's processing may be contributing to what you see.

The pattern does not reach the edges

The TV may be enlarging the picture slightly, a behavior often called overscan. The computer may also be using a non-native resolution or scaling setting. Check whether the desktop's edges are cut off, and adjust the TV and computer settings below.

The pattern looks different from the computer screen

TV picture processing, HDR, color range and picture modes can make the same browser pattern look different on two screens. A visual comparison can show that the displays differ, but it cannot tell you which one is color-accurate.

Fix the display before retesting

1. Confirm the TV is the selected display. On Windows 11, open Settings › System › Display, select Identify, then click the TV's numbered display. On macOS, open System Settings › Displays and select the TV. If you mirror displays, temporarily use an extended desktop so you can identify the TV separately.
2. Choose the TV's native resolution. In Windows 11, select the TV in Settings › System › Display and choose the resolution marked recommended. On macOS, open System Settings › Displays and choose a resolution that matches the TV's native setting. A lower or mismatched resolution can make edges and pixels look less clear.
3. Set the TV to show the full computer image. In the TV's picture or screen-size menu, look for a setting such as Just Scan, Screen Fit, 1:1 or Full Pixel. Names vary by TV. Avoid zoom or overscan modes when you want the whole desktop visible.
4. Check the computer's scaling. In Windows 11, go to Settings › System › Display › Scale. On macOS, open System Settings › Displays and review the resolution options. Scaling changes the size of interface elements, not the TV's physical pixel count, so do not use it to judge whether the panel has a bad pixel.
5. Temporarily turn off picture enhancements. In the TV's picture settings, try disabling features such as dynamic contrast, noise reduction, motion smoothing and vivid picture modes. These can alter a test pattern. You can turn them back on after checking.
6. Check HDR and the HDMI connection. If colors look washed out or unusually dark, turn HDR off temporarily in the computer's display settings and retest. Reseat the HDMI cable or try another port if the image flickers, shifts or has missing edges.

When the TV may have a panel fault

A single visible pixel does not always qualify for a warranty replacement, and manufacturers set their own defect policies. Take a photo of the screen with the pattern visible, note the input and settings, and check the TV's warranty terms before attempting repairs. Do not press or rub the panel to try to change a pixel, because pressure can cause further damage.

Why a TV can change the pattern

A browser draws the pattern, but the TV may process it before it reaches the panel. Picture modes can raise contrast, smooth motion or alter color. The TV may also overscan a computer signal unless its input is set to a PC or game mode. These settings can make a pattern look different without indicating that the screen itself is defective.

Use the patterns to find visible issues, then retest at the resolution and picture settings you normally use with the TV as a monitor.