Hold a piece of pure white paper perpendicular to your monitor screen. Do not place it flush against the screen. Hold it on an angle. The background color for this Web page is pure white.

If you are seeing a very pale greyish or bluish color, your computer does not view colors accurately. If you do not have a pure white, every color is affected. You have the "Sunglass Syndrome".

Consider this: Even if you have perfect color vision, if you're wearing sunglasses, you will still see thousands of colors, but those colors are not the actual color. They are being filtered through the dark lens. Unfortunately many computer systems have a similar color blindness. In many cases, the monitor is the primary cause of this effect.