R plots: use dark borders around colored points -

i have data have plot coloured points, , dark border around points. here code:

plot(x, y, pch=c(rep(16, 6), rep(17, 6)), cex=1.3, col=my_colors) 

this produces coloured points without border... how can add dark border?

use fill-able plotting characters instread of solid ones.

x<-1:6 y<-1:6 my_colors <- rainbow(6)  plot(x, y, pch=c(rep(22, 3), rep(23, 3)), cex=1.3, bg=my_colors)