getcolors: Choosing colors visually
In basille/basr: Basic, but hopefully useful, functions

Description Usage Arguments Details Value Original URL Author(s) Examples

Allows for the selection of n colors by using a simplified color swatch.

1	getcolors(n)

`n`	The number of colors to choose

getcolors allows selection with a mouse using the locator function. Following selection, a second plot opens showing how these colors look next to each other and on a background gradient of black to white. The function uses an RGB color model: Red increases on the y-axis, Green increases on the x-axis, and Blue is a repeated sequence of levels across the x-axis.

A character vector with elements of 7 or 9 characters, "#" followed by the red, blue, green and optionally alpha values in hexadecimal (after rescaling to 0 ... 255). The optional alpha values range from 0 (fully transparent) to 255 (opaque).

http://menugget.blogspot.com/2013/01/choosing-colors-visually-with-getcolors.html

Marc in the box

## Not run: 
set.seed(1)
n <- 100
x <- seq(n)
y1 <- cumsum(rnorm(n))
y2 <- cumsum(rnorm(n))
y3 <- cumsum(rnorm(n))
y4 <- cumsum(rnorm(n))
ylim <- range(c(y1, y2, y3, y4))

cols <- getcolors(4)

plot(x, y1, ylim = ylim, t = "l", col = cols[1], lwd = 3, ylab = "")
lines(x, y2, col = cols[2], lwd = 3)
lines(x, y3, col = cols[3], lwd = 3)
lines(x, y4, col = cols[4], lwd = 3)
legend("topleft", legend = paste("y", 1:4, sep = ""), col = cols,
    lwd = 3)
## End(Not run)