In a large mixing bowl, combine warm water, starter, sugar, salt, yeast, and oil. Stir well to dissolve the sugar and salt.
Gradually add one cup of flour at a time to the mixture. Stir the dough until it becomes sticky and begins to come together.
Leave the dough in the bowl and cover it with a clean kitchen towel or plastic wrap. Allow the dough to rise in a warm area until it has doubled in size. This usually takes about 1-2 hours, depending on the temperature.
Preheat your oven to 350°F (175°C).
Sprinkle a little flour on a flat surface and sides of the dough. Gently push your hands between the dough and the bowl to release the dough without deflating it.
Transfer the dough to a sheet of parchment paper. If the dough deflates during the transfer, let it rise again until it doubles in size.
Mix your colors with the white to slightly brighten and thin out. Add 1 drop of white at a time until the desired color is achieved. For grey shadowing if desired, Mix a little bit of green, red, and yellow until grey is achieved.
As your dough sits on the sheet of parchment, begin to paint your loaf. I like to practice on a sheet of paper first using watercolors.
Use a sharp knife to score the top of the dough if you want.
Place the Dutch oven in the oven for 5 minutes to preheat, then place the parchment and loaf into the Dutch oven.
Bake for 30 minutes with the lid on, then remove the lid and continue baking for 10 or until the top turns golden brown.
Remove the bread from the oven and let it cool on a wire rack before slicing and serving.
Enjoy your homemade bread!