Color representation is more determined by panel type. Usually IPS panels have better color representation an that is even more important if the output of the content is going to be actually printed as photoes or posters and such, like book covers for example. I would focus on the following than refresh rate (Hz).
Another factor is color depth (8-bit versus 10-bit). Monitor with higher color depth (this varies based on brand and model) show higher number of color shades. In other words they show more color, more detailed fading of color if you like; that is, the fading is more gradient.
Also important is color space. Color depth as I said is the number of gradients between white and red, for example. The color space determines how red...