Coloured Pastas have such strong flavours that they require their own special sauce, example, the burnt sage butter sauce complements the beetroot pasta, a Ragù of oxtail; will go perfectly with capsicum pasta, the examples are endless.
Beetroot, spinach, butternut should be pureed with the eggs and the most important thing is that the pureed ingredient must be completely cooled before it is added to the eggs and then placed in the flour well.
The pasta dough is kneaded and rolled in the usual way (see Basic Pasta Dough) though some additives e.g. pepper, will reduce the elasticity of the pasta, so you may not be able to make the sheets as thin as you can as with the plain pasta. Be careful as your sheets of pasta can tear as well.
Some examples are spinach, beetroot, mixed herbs, squash, pumpkin, chocolate(yes), squid ink, lemon rind, orange rind and pepper. Be adventurous!