What color combination is best for reading on a sheet of paper?

Asked by Ltryptophan (12091) September 18th, 2021 from iPhone

For instance, most books I’ve ever read are black text on white paper.

If I’m not mistaken green is the easiest color for the eye to see. Would green text be optimal?

Since we are used to black and white, maybe that’s the least distracting.

I guess this would also apply to backlit displays, but maybe the effect of the additional light source changes something.

By optimal I mean: least eye strain, most visible, perhaps mood effect…

Just thinking about this I get the idea of books written with color in mind on the page to enhance what is being read.

Hero going into an enchanted forest? The pages get darker, the words just perceptible. Hero receives some great honor? The letters are gold foil against the hero’s representative color.

But, I’m interested more in which two colors would be optimal for the eye, instead of maybe cost considerations. Perhaps black ink is least expensive, perfectly sufficient, and a new color could only lessen eye fatigue imperceptibly.