Identify Closest Match to a Color Given by a Hexadecimal String

Given a color as a hex string #rrggbb, find the closest match in the table of known (named) colors.

HexToCol(hexstr, method = "rgb", metric = "euclidean")

Arguments

hexstr: a color or a vector of colors specified as hexadecimal string of the form "#RRGGBB" or "#RRGGBBAA"
method: character string specifying the color space to be used. Can be "rgb" (default) or "hsv".
metric: character string specifying the metric to be used for calculating distances between the colors. Available options are "euclidean" (default) and "manhattan". Euclidean distances are root sum-of-squares of differences, and manhattan distances are the sum of absolute differences.

Details

Finds the color with the minimum squared distance in RGB space.

Value

The colorname(s) of the closest match(es) (if more than one).

Author

Ben Bolker, vector support Andri Signorell <andri@signorell.net>

Examples

ColToHex(c("lightblue", "salmon"))
#> [1] "#ADD8E6" "#FA8072"

HexToCol(c("#ADD8E6", "#FA1572"))
#> [1] "lightblue" "deeppink2"
HexToCol(Pal("Helsana"))
#>  [1] "deeppink4"    "darkorange2"  "goldenrod1"   "navajowhite3" "hotpink3"    
#>  [6] "skyblue3"     "gold3"        "gray80"       "gray40"       "white"       

x <- ColToRgb("darkmagenta")
x[2,] <- x[2,] + 155
RgbToCol(x)
#> [1] "gray57"