Bake cookies. Prepare cookie dough following recipe instructions, omitting Red and Green Candy Melts candy and holiday sprinkles. Divide dough into three equal portions.
Using Pink, Lemon Yellow and Violet icing colors, tint one portion each pink, yellow and violet. Place each portion of dough in separate 16 in. decorating bags. Cut ¾ in. tip in each bag.
Prepare cake pan with non-stick spray. Pipe pink cookie dough in pan in loose zig-zag. Using wet spatula, spread dough evenly in pan. Repeat with yellow dough, then violet dough.
Bake and cool. Remove from pan.