At left is displayed the web color gainsboro. Gainsboro is a pale tone of gray. There is no evidence the name gainsboro was used as a color name before it was included as one of the X11 colors when they were formulated in 1987.

The colors white and black are not usually thought of as shades of gray, but they can be thought of as shades of achromatic gray, as both contain equal amounts of red, blue and green. White is at the extreme upper end of the achromatic value scale and black is at the extreme lower end of the achromatic value scale, with all the colors normally considered tones of achromatic gray colors in between. Since achromatic colors have no hue, the hue code (h code) is left blank for achromatic colors (usually marked as a dash).