We evaluate the colour quality of the AOC 90-series based on a few different aspects.
First we take a look at the coverage of the sRGB colour space. AOC claims about 130% coverage of the sRGB-triangle for the Q2790PQU and about 100% for the I2490PXQU and the I2790PQU. Because we measure in the standard mode (the way the monitor is configured out-of-the-box) relative to the colour space that is most closely achieved, we end up at 95.8% of the DCI P3 colour space with the Q2790PQU; this colour space is a lot bigger than sRGB. The two full hd-models are slightly below 100% of the sRGB standard. What this means is that the colours of the Q2790PQU are especially saturated - more than desirable for sRGB-coverage.
Secondly we look at the colour temperature of white with the standard setting. This is quite good with all three models, although none of them are completely 100% identical to the desired 6500 K. THe two full hd-monitors are slightly cooler, albeit not noticeable, while the qhd-monitor is slightly warmer.
We measure the colour- and grey deviation based on the CIE2000 standard and also take a look at the standard deviation. Simply put this gives you an indication of the extent of which the sub measurements on which the average deviations are based, deviate from that average measurement. Aside from that the averages are now based on considerably more sub measurements. These can be found in the print screens for every tested product. You can also find the so-called saturation sweeps there. These show in what manner the main- and support colours, meaning RGB and CMY, deviate from the desired values in a continuum.
The three AOC 90-series monitors perform remarkably well in terms of colour deviation, where especially the two 27-inch models show a remarkably small colour fault. The 24-inch model does not perform as well as the other two, but it is still well below the value of 3 that we keep to as visible for the human eye. This monitor does have the least variation in the sub measurements, as is shown by the very low standard deviation.
For a long time the grey adjustment was a big challenge for a lot of monitors, but AOC shows they have learned how to do this by now. The Q2790PQU has the worst score at slightly below 3, which is still very good; the two full hd-monitors show exceptional values, where the I2790PQU has earned a special mention.
None of the models have an sRGB-mode, which means they have not been tested using one. Because of the slightly over saturated nature of the Q2790PQU we would not recommend it for image editing as its primary use, but it is certainly suited for regular daily use.
Detailed measurements standard mode
Below you can clearly see that the Q2790PQU has a wider colour range.
Gamma and grey values
The gamma-value of the I2490PXQU is slightly too high on average, the other two are slightly too low. The gamma curves - which you can find below - show that AOC can still improve when it comes to this, but for daily use you will not notice this.
Standard gamma and grey values
From left to right: I2470PXQU, I2790PQU, Q2790PQU. The gamma curve is not perfect, but the grey deviation is very small, which results in a fairly neutral white.