Default Color Presets
Like usual I have made a chart with the default preset measurements. I used HCFR for the gamma/contrast values and BasICColor for everything else. I also verified the brightness and color temperature with i1 Profiler using my new i1 Display Pro colorimeter which provides accurate the correct color temperature and brightness values.
The Game and Night View presets present washed out colors thanks to the low gamma. Night View looks even worse than the Game preset due to the high black level resulting in grey blacks and a very dull picture. Game mode succeeds at revealing details in dark areas while still looking natural. The Game preset could be useful for pro-gamers wanting the slight visibility edge in games, but the picture quality suffers.
The Theater mode greatly over-saturates colors while also crushing some dark details. The picture still looks natural but is far to vibrant. Dark scenes details are swallowed in blackness when using the Theater preset. Below I have taken a picture comparing the Theater preset to a calibrated monitor.
Theater Mode=Perfect for over-saturation lovers
The Standard mode provides the most natural looking picture, it is essentially perfect except for the slight green tinge which leads to some banding in this Lagom test: http://www.lagom.nl/lcd-test/gradient.php. Most monitors seem to suffer from a strong green dominance, including the last 120hz monitor I tested, the Samsung S27A950D. All of the Asus's presets have this problem but it was only visible in test images.
When looking at the above photo VS. a calibrated monitor the green tinge was barely noticeable. Still, the Asus could do better in this regard since monitors like the HP2509B, Acer G245H and LG W2422PA I tested all provided natural tinge free color presets.
The Scenery preset allows for the most adjust-ability in the monitors OSD and provides a very natural image. However due to the lower gamma it looks slightly washed out compared to the standard mode. There is a simple fix for this however, you just have to set the colors to Warm and the picture is essentially perfect apart from the slight green tinge.
To sum things up the Asus provides near perfect color presets in the Standard and Scenery presets. The main problem was the slightly low gamma, minor green tinge and need to set the Scenery modes colors to Warm in the OSD. It is very easy to look past these flaws because the Asus VGH236H provides a very natural, vibrant and clear image thanks to the accurate colors, good black level and glossy screen.
Color Preset Chart May 2015 by thedeepinthesky, on Flickr