Web usability isn’t all about navigation and function. Choice of colors also matter. Some combination of color may make user’s eye works harder.
For example, nothing can beat black text on white background. Black and white has the maximum contrast so there’s nothing should go wrong if you use these colors. User should see or read easily. But sometime we need some touch outside the comfort zone of black and white.
Whatever color we chose, remember to use the combination of light and dark color. Light font with dark background or vice versa. Forget about experimenting with slightly contrast colors. Users have their own browsers and monitors that have their own way to render color. So the safest one is to play it with high contrast colors all the time.
About eye catching color such as red, it may be good to attract user’s attention, but we also must really careful in using this kind of color. If you use it too much, it may hurts someone’s eye and drive them away.