One of the easiest color combinations to read is a dark brown text on cream background. OR, for one of the easiest ways to reduce eye strain, ask an ophthalmologist to CHECK your reaction to colored tints, beginning with the RGB basic tints that I can get practically anywhere. If you have a ten percent tint that suits you, it's easier than finagling a dozen settings in IE JUST for colors.

Look for someone who understands vision processing disorders and the eyestrain THAT generates, or migraines and light sensitivity, based on your own experiences. (I know people who have both issues, comorbidly.)