Divide the dough into three equal parts.

Work the red color into one portion of the dough, then the blue into another. Leave the third plain.

Shape into flat rectangles, all approximately the same size.

Individually wrap all three pieces with plastic cling film and place in the fridge for at least a half hour.

Roll out the red dough into a thin large rectangle on a lightly floured surface.

Repeat with the un-tinted dough and gently lay it on top of the red dough.

Repeat with the blue portion, laying it gently on the plain cookie dough layer.

Using a sharp knife, trim the edges all around to make all edges straight.

Starting at the wide end of the dough layers, roll the dough into a log.

Wrap in plastic cling film and place in the fridge for at least an hour.

Preheat oven to 350 degrees F.

Line two baking sheets with parchment paper.

Remove from fridge and using a sharp knife, slice the log into pieces and lay them on the baking sheets.

Sprinkle with sanding sugar if desired.

Gently squish the scraps together and roll them out on the floured surface.

Use a cutter to make shapes, sprinkle with sanding sugar (optional) and place on baking sheets.

Bake for approximately 8 minutes. Remove from the oven right before the cookies start browning.

Transfer to a wire rack and let cool completely.