There are also yellows and all the intermediate shades up to red. Those will be red under the microscope. All the different colored materials are the macerals. Those are coalified spores. Those are coalified plant cuticles.
Cuticles are a plant's idea of skin.
They prevent moisture loss and resist damage by microorganisms to the underlying material. It is often found on the leaves of plants. The red material is the remains of the woody tissues of plants, such as the trunk and roots of trees. The type of material you see in the photos can be found in any coal chunk that you pick up. What will vary is the amounts and types of the different macerals.