Color Accuracy and Gamma

Color space and screen uniformity

We start our tests by measuring color space and screen uniformity. Uncalibrated performance means the out-of-the-box settings a monitor ships with. Calibrated performance is what results after the monitor has been put through our DataColor Spyder calibration process. Our aim with calibration is to be at a Gamma of 2.2 with a target 6500k color temperature and an aim of 120cd/m2 brightness. Luminance is candelas per square meter (cd/m2), also described as 'nits'. By default, the screen is setup in Racing mode.

sRGB - The monitor defaults towards the racing setting with DCI-P3 (wide color gamut) enabled as opposed to sRGB, which we enabled above. While this mode is less visually striking, it accurately reflects the original colour design of a game or movie, which is typically mastered in this color space (unless playing in HDR). This mode is also advantageous for content creation, ensuring your photos or videos appear consistently on various displays. However as colour accuracy will show, if you need precise colours, this monitor ain't the best.

DCI-P3 - With the setting back to defaults, DCI-P3 is enabled. The sRGB range is fully covered; Adobe RGB (close to DCI-P3), is ar 91% and DCI-P3 is filled 96% straight out of the box, not 100% as ASUS claims.

Again we used the default Racing mode, the default provided by the manufacturer, and the overall WIDE gaming setting of color data across various modes. And that brings us to DCI-P3 at 96% coverage. The display is marketed as having DCI-P3 coverage, but its actual "Wide Gamut" range falls between DCI-P3 and BT.2020 HDR, meeting the minimum coverage requirements for DisplayHDR 1000 and UHD Premium. The color setting is not directly calibrated to a specific gamut like sRGB. The monitor comes pre-calibrated from the factory with good sRGB accuracy, defaulting to 8 bits per color out-of-the-box. The "wide gamut" options do not precisely correspond to either DCI-P3 or BT.2020, but this is not a concern for professional or prosumer monitors.

Once we calibrate the screen we squeeze a fraction more out of the monitor to 97%, but it's still not the advertised 100%

Gamma

These monitors come factory calibrated for you; we aim for a gamma of 2.2, which is also the default for the ASUS configuration.

Gamma deviation straight out of the box at factory settings was off, close at 1.6 even; there is an allowance deviation of 10%. This monitor is untouched out of the box aside from a rest back to firmware defaults. Of course, you can alter and tweak anything to your liking as the monitor has selectable gamma modes. 

Racing mode @ sRGB 

Racing mode @ DCI-P3 

Color Accuracy Concerns in Asus' Flagship OLED Monitor

Asus faces challenges in color accuracy, with the PG27AQDM OLED monitor exhibiting greater color inaccuracies compared to competitors. These discrepancies are noticeable in certain situations, such as when displaying lighter skin tones, which appear somewhat dull or unhealthy. While these issues are subtle enough that most users might overlook them, it's worth noting that this is a $1,000 monitor – a flagship OLED display from Asus with less than impressive colour accuracy.

ASUS advertised a colour-accurate delta <2.0 or better. From a practical perspective, the average human eye cannot detect color differences with a Delta-E value of 3 or less. An exceptionally trained and sensitive human eye can only perceive color differences with a Delta-E of 1 or above. The monitor is excellent at an △E<1 average.  The screen, however, is off by a mile.

Additional concerns arise regarding color temperature and gamma performance. The monitor's out-of-the-box color temperature measures 6700K~7150, which is noticeably cooler and more sterile than the ideal 6500K.