Shades of gray

Variations of gray or grey include achromatic grayscale shades, which lie exactly between white and black, and nearby colors with low colorfulness. A selection of a number of these various colors is shown below.

Below is a chart showing the computer web color grays. An achromatic gray is a gray color in which the red, green, and blue codes are exactly equal. The web colors gray, gainsboro, light gray, dark gray, and dim gray are all achromatic colors. A chromatic gray is a gray color in which the red, green, and blue codes are not exactly equal, but are close to each other, which is what makes it a shade of gray.

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).

White is a color, the perception of which is evoked by light that stimulates all three types of color sensitive cone cells in the human eye in equal amounts and with high brightness compared to the surroundings. A white visual stimulation will be void of hue and grayness. White is the lightest possible color.

Achromatic grays are colors in which the RGB (red, green, and blue) values are exactly equal. Since achromatic grays have no hue, the hue code (the h in the hsv values of the color) is indicated with a dash. Achromatic grays are the axis of the color sphere, with white at the north pole and black at the south pole of the color sphere. The various tones of achromatic gray are along the axis of the color sphere from white at the top of the axis to black at the bottom of the axis.

At right is displayed the color gray.

The first recorded use of gray as a color name in the English language was in 700.

This tone of gray (HTML gray) is universally used as the standard for gray because it is that tone of gray which is halfway between white and black.^{[citation needed]}