"red pen" = PEN (size=7 color="red");
"blue pen" = "red pen" (color="blue");
"yellow pen" = "red pen" (color="yellow");
"green pen" = "red pen" (color="green");
"eraser" = ERASER (size = 75);

"Core Pointer" = "red pen";
"Core Pointer"[SHIFT] = "blue pen";
"Core Pointer"[CONTROL] = "yellow pen";
"Core Pointer"[META] = "green pen";

"Core Pointer"[2] = "red pen" (arrowsize=2);
"Core Pointer"[2 SHIFT] = "blue pen" (arrowsize=2);
"Core Pointer"[2 CONTROL] = "yellow pen" (arrowsize=2);
"Core Pointer"[2 META] = "green pen" (arrowsize=2);

"Core Pointer"[3] = "eraser";
"Core Pointer"[3 SHIFT] = "eraser" (size = 150);