Amazon has this Post-it Page Markers, 1/2 in x 1 3/4 in, Assorted Fluorescent Colors , 50 Sheets/Pad, 5 Pads/Pack (670-5AF)
For $1.67 as an add on item
Post-it(R) Page Markers in assorted colors and 1/2 in x 2 in size are ideal for the temporary marking of reference materials. They stay put until you decide to move them. The rainbow of colors in every pack are easy to spot and easy to write on. Works like a note and flag combined. Contains 50 sheets/pad and 5 pads/pack.