There are 5 colors to paint your queens, the color you use depends on what year the queen was born in. Years ending in 1 and 6 are white, 2 and 7 are yellow, 3 and 8 are red, 4 and 9 are green, 5 and 0 are blue.
"When You Read Good Books" is how I remember this.
You can buy queen marking pens, but we just used child safe paint (i.e. non-toxic) and a small paint brush.
Not too shabby for a first mark.