The cells produce and maintain their intercellular matrix, which in turn provides physical support and protection and a pathway for diffusion to and from the cells themselves. The standard tissue stain is composed of hematoxylin and eosin.
Clear areas represent water, carbohydrate, lipid, or gas.
Try to understand what you are seeing. Nuclei will always stain blue with the hematoxylin. The cytoplasm of cells will stain according to its composition. The strong supporting proteins around the cells will stain pink, and you will be able to see their texture. In all but the most regular of tissues, between the fibers will be looser areas where there is a proponderance of ground substance.