Mix flour, salt, yeast and bread improver into a large bowl.

Make a well in the centre of the flour mixture and pour in the water and olive oil and mix well.

Tip the dough mixture out onto a well-floured surface and knead for around 10 minutes until soft and smooth.

Divide dough into equal portions according to how many colors you have.

Place each piece of dough into a separate bowl and cover with plastic wrap or a damp tea towel.

Take one piece of dough and add a few drops of food coloring to it. Wearing plastic gloves, start working the color through the dough, continuing until it is evenly colored throughout. Place it back in its bowl and cover.

Repeat the process with the remaining pieces of dough.

Now let the dough rest for around 15 minutes.

Once the dough is rested, take each piece one at a time and roll it out on a well floured surface into a large rectangle.

Stack each rectangular piece of dough on top of one another and roll it all up into a large scroll.

Place the dough into a lightly oiled bread tin and leave to prove in a warm place (see notes) until it has risen to the top of your loaf tin.

Pre-heat the oven to 360F / 180C.

Bake the bread in the oven for 25 minutes. It should sound hollow when you tap it.

Remove the bread from the tin immediately and allow to cool on a rack.

Allow to cool completely before slicing.