To get the best input lag possible when gaming, you need to set the 'Picture Mode' to 'Game'. In 'Game' mode, some options won't be available in the setting pages, since the 'Game' picture mode disables most of the image processing to give better input lag. Under game mode, the color temperature setting is now a slider giving you a different control from colder to warmer, but the most accurate results are with a setting of W40. The gamma selection is also a bit different, giving you the option from 'Low' to 'High2', and the most accurate setting is Medium. For the rest of the available settings, you can follow our general settings.
Update 02/18/2019:
There is currently a bug with 'Game' mode. When 'Game' mode is enabled, the color gamut is locked to 'Wide'. With SDR content this can result in over saturated images. To avoid this issue, use the 'ISF Expert (Dark Room)' Picture Mode, with the input label set to 'PC'. This will give the same low input lag as game mode, but with full control over the color gamut and other picture settings.