Colour utilities

alphacol adds an alpha value to a colour specification and convert to a hexadecimal colour string.

alphacol(col, alpha = FALSE)

Arguments

col	vector of any of the three kinds of R color specifications, i.e., either a color name (as listed by colors()), a hexadecimal string of the form "#rrggbb" or "#rrggbbaa" (see rgb), or a positive integer i meaning palette()[i].
alpha	logical value indicating whether the alpha channel (opacity) values should be returned.

Examples

# Alphas
alphacol('red') # do nothing
#> [1] "#ff0000"
alphacol('red', 10)
#> [1] "#ff0000a"
alphacol('#aabbcc', 5)
#> [1] "#aabbcc5"
alphacol(4, 5)
#> [1] "#2297e65"