Line a baking sheet with parchment paper or wax paper.
Melt the yellow candy melts according to the package instructions. Dip one flat side of each cookie into the candy melts then place it on the baking sheet. Refrigerate the cookies for 5 minutes until the candy melt has fully hardened.
Melt the blue candy melts according to the package instructions. Dip the lower one-third of each cookie into the candy melts then return it to the baking sheet. Transfer a portion of the melted candy melts into a piping bag, snip off the tip and pipe the straps of the overalls. Refrigerate the cookies for 5 minutes until the candy melt has fully hardened.
Melt the black candy melts according to the package instructions. Transfer the candy melts to a piping bag, snip off the tip and pipe a variation of mouths (smiling, frowning, scowling, etc.) onto the cookies above the overalls. Next, pipe a variation of hairstyles at the tops of the cookies, then pipe a line (below the hair) across each cookie and immediately place two small eyes or one large eye on each cookie. Refrigerate the cookies for 5 minutes until the candy melts have fully hardened then serve or use as a cupcake topper.