Which is the most suitable colour of light during reading from the healthiness of human eyes?

I would say white light, to increase the contrast between the paper and the writing, any other color and your eyes would be straining more.

I have also found that it is good to have a dimmer contrast on the computer screen and when you can change font color find one that isn't harsh on the eyes. I have my computer layouts on a maroon and sage theme and it doesn't hurt my eyes as much as the blue and grays.

High contrast is very good for some. The person reading would know what was best. I live in very dim lighting. But when I read, natural (coming through) the window is best.