When your sourdough loaf is done proofing in the fridge, take it out and turn out onto a piece of parchment paper
Make sure the surface is not covered in a large amount of flour - if it is, gently brush excess flour off, to make the surface as even as possible
Prepare a small glass of water and a plate (or a clean palette) for your food coloring gel colors
Squirt a little bit of each color you want to use onto the plate. Use white food coloring to brighten the color shades. Use a little water or alcohol to dilute the gel colors.
Dip your brush and let your imagine run wild! Heart for Valentine's Day, hand-painted flowers or a bouquet of spring flowers for Easter.
Once your pain dries, you can go back over to add shading or any other details.
Score your bread and bake as usual (if you need a sourdough recipe, check out THIS POST)