Resolution and bit-depth settings: LCD panels are best run at their ‘native’ (maximum) resolutions. Most LCD displays support lower resolution modes for compatibility with older video cards, but it may interfere with color rendition as well as image sharpness if you run the display at lower settings.
If you’re not certain whether you’re running at maximum, it’s a good idea to check this and that you’re running the display at maximum color (bit) depth – see your operating system help for how to do this, but you should have ‘millions’ of colours, 24- or 32-bit selected.