stock_color = "lightgray";

bushing_od = 12;
bushing_id = 8;
bushing_len = 8;

module bushing() {
  colorize(stock_color) {
    difference() {
      cylinder(d = bushing_od, h = bushing_len);
      translate([0,0,-1])
	cylinder(d = bushing_id, h = bushing_len + 2);
    }
  }
}

module colorize(colorname) {
  if (use_colors) {
    color(colorname) union() { children(); }
  } else {
    children();
  }
}