Grey

From Wikipedia, the free encyclopedia

This article is about the color; for other uses of "grey", see Grey (disambiguation).

For other uses of "gray", see Gray (disambiguation).

Grey
— Color coordinates —
Hex triplet		#808080
RGB^B	(r, g, b)	(128, 128, 128)
CMYK^H	(c, m, y, k)	(0, 0, 0, 50)
HSV	(h, s, v)	(-°, 0%, 50%)
B: Normalized to [0–255] (byte) H: Normalized to [0–100] (hundred)

Grey or Gray (see spelling differences) is the color between white and black. It is a color seen commonly in nature. In pigment, or subtractive color (CMYK), it is created by adding black. In light, or additive color (RGB), it is created by adding equal amounts of R, G, and B, with R,G,B greater than 0% and less than 100% (greater than 0 and less than 255, in the 8-bit notation commonly used in computing). Depending on the color temperature of the light (measured in kelvins of a black body radiator), the human eye can interpret the same object as either grey or some other color, with colder light adding a yellow-orange hue and warmer light adding a blue hue.

Two colors are called complementary colors if grey is produced when two colors are combined. Grey is its own complement. Consequently, grey remains grey when its color spectrum is inverted, and therefore has no opposite, or alternately is its own opposite. On a more abstract level, it could be argued that colors which produce grey when mixed, such as black and white, are the opposite of grey while separated. However, this could not be considered the literal opposite of grey.

[edit] Color coordinates

RGB

All the grey values in greyscale are solutions of the inequality:

$0 \le ( R = G = B ) \le 255$

CMYK

All the grey values in greyscale are solutions of the inequality:

$0 \le K \le 255$ when $C = M = Y = 0 \,$ .

In theory it is also possible to achieve a greyscale with perfect inks when:

$C = M = Y \,$ and $K = 0 \,$

HSL

All the grey values in greyscale fit one of the following three equalities:

S = 0

L = 0

(black) or

L = 1

(white).

HSV

All the grey values in greyscale are solutions of the inequality:

$0 \le V \le 1$ when $H = S = 0 \,$ .

[edit] Web colors

There are several shades of grey available for use with HTML and CSS. Oddly, all are spelled with an a except lightgrey: this can cause unexpected errors (this discrepancy is inherited from the X11 color list). Note that the three "slategray" colors are not themselves on the greyscale, but are slightly saturated towards cyan (green + blue).

HTML Color Name	Sample		Hex triplet
	(rendered by name)	(rendered by hex triplet)
lightgrey			#D3D3D3
gray			#808080
darkgray			#A9A9A9
dimgray			#696969
lightslategray			#778899
slategray			#708090
darkslategray			#2F4F4F