What is Colour Accuracy?
Colour accuracy measures how closely a monitor's output matches the intended colour values. The standard metric is Delta-E (ฮE) โ the perceptual distance between the displayed colour and the reference. A Delta-E below 2 is considered imperceptible to the human eye; below 1 is excellent. Above 3 is visibly inaccurate.
Consumer monitors typically ship with a Delta-E average of 2โ6. Factory-calibrated panels, marketed as "99% sRGB" or "hardware-calibrated", target Delta-E below 2. Colour-critical work โ photo retouching, print production, video grading โ requires a calibrated, profiled display.
How to Use the Colour Accuracy Test
Step 1 โ Launch and go fullscreen. Press Launch Test, then F for fullscreen.
Step 2 โ Check primary and secondary colours. Cycle through solid red, green, blue, cyan, magenta, and yellow. Each should appear vivid and distinct โ not shifted toward adjacent hues.
Step 3 โ Evaluate the grey ramp. Navigate to the greyscale ramp. Each step from black to white should be neutral โ no colour cast. A pink, green, or blue tint in the greys indicates a white balance problem.
Step 4 โ Check the skin tone patch. If available, a skin tone swatch reveals warm/cool bias. A green or cyan shift in skin tones is the most common visible failure mode.
Colour Accuracy by Panel Type
| Panel | Typical Delta-E (out of box) | sRGB Coverage |
|---|---|---|
| Budget TN | 3โ6 | 90โ95% |
| Standard IPS | 2โ4 | 95โ100% |
| Factory-calibrated IPS | < 2 | 99โ100% |
| Wide-gamut IPS | 1โ3 (native) | 100%+ (DCI-P3) |
| OLED | < 1.5 | 100%+ |
Improving Colour Accuracy
The OSD colour temperature setting has the largest effect. Warm presets (around 6500K) are closer to the D65 white point used in sRGB content. Cool presets run blue and inflate perceived inaccuracy.
Check that your monitor colour profile is correctly assigned in the OS display settings. The wrong ICC profile is a common cause of visible colour casts even on accurate panels.
For professional use, hardware calibration with a colorimeter establishes a custom ICC profile matched to your specific unit, correcting both white balance and the tone response curve.
Frequently Asked Questions
What Delta-E is acceptable for photo editing? Delta-E below 2 is the professional standard for photo editing. Below 1 is excellent. For casual use, Delta-E up to 3โ4 is acceptable. Most factory-calibrated monitors marketed for creative work target ฮE < 2.
Does sRGB coverage matter? Yes for SDR content. A monitor with 95%+ sRGB coverage displays web images, video, and most games as intended. Wide-gamut panels (DCI-P3, Adobe RGB) display more saturated colours but require correct colour management to avoid oversaturation on sRGB content.
How do I know if my monitor is colour accurate? Visual inspection with test patterns reveals obvious problems. Objective measurement requires a colorimeter and profiling software โ DisplayCAL is free and works with most hardware calibrators.
Why does my monitor look different from other screens? Each panel has unique colour characteristics shaped by its backlight, filter set, and factory calibration. Consistent results across multiple displays require hardware calibration on all units and the same colour profile applied in the OS.