#' Explore color palettes

#'

#' @export

#' @importFrom grDevices col2rgb

#' @importFrom dichromat dichromat

#' @name palette_explorer

#' @rdname palette_explorer

#' @example ./examples/palette_explorer.R

#' @references \url{http://www.color-blindness.com/types-of-color-blindness/}

palette_explorer <- function() {

#' Get and plot a (modified) Color Brewer palette

#'

#'

#' The default contrast of the palette depends on the number of colors, \code{n}, in the following way. The default contrast is maximal, so \code{(0, 1)}, when \code{n = 9} for sequential palettes and \code{n = 11} for diverging palettes. The default contrast values for smaller values of \code{n} can be extracted with some R magic: \code{sapply(1:9, tmaptools:::default_contrast_seq)} for sequential palettes and \code{sapply(1:11, tmaptools:::default_contrast_div)} for diverging palettes.

#'

#' @param n number of colors

#' @param contrast a vector of two numbers between 0 and 1 that defines the contrast range of the palette. Applicable to sequential and diverging palettes. For sequential palettes, 0 stands for the leftmost color and 1 the rightmost color. For instance, when \code{contrast=c(.25, .75)}, then the palette ranges from 1/4 to 3/4 of the available color range. For diverging palettes, 0 stands for the middle color and 1 for both outer colors. If only one number is provided, the other number is set to 0. The default value depends on \code{n}. See details.

#' @param stretch logical that determines whether intermediate colors are used for a categorical palette when \code{n} is greater than the number of available colors.