The boxplot.default() function ignores argument 'boxfill' passed by user: x <- rnorm(100) boxplot(x, boxfill="blue") boxplot(x, pars=list(boxfill="green")) As the original creator of the 'boxfill' argument, I'd like to propose the following change to the if(plot) clause in boxplot.R: if(plot) { if(is.null(pars$boxfill) && is.null(args$boxfill)) pars$boxfill <- col do.call("bxp", c(list(z, notch=notch, width=width, varwidth=varwidth, outline=outline, log=log, border=border, pars=pars, horizontal=horizontal, add=add, at=at), args[namedargs])) invisible(z) } What I've done is (1) setting boxfill=col only when that is desired, (2) named the 'width' list element to avoid confusion, and (3) rearranged the list so it has the same order as args(bxp). Thanks, Arni R 2.4.0-patched on WinXP