If you spend just a few minutes in front of any cheese case, you will probably be struck by how different the cheeses look.
They are of different sizes (from a 4 oz chèvre button to a 50 lb cheddar); different shapes (truncated pyramids, flat brie, spherical Mimolette), and also different colours (bright white fresh goat cheese, juicy red Red Leicester, golden Appalachian, and fudge-brown Gjetost).
The size and shape of the cheese, is normally determined by the mould or cloth used to hold the curd while the cheese's form is created, and the moulds are usually chosen to match the type of cheese being made.
You don't get tiny cheddar pyramids for a reason - cheddars just can't be made that way.
The colour of cheese is controlled by different factors, and the final colour of a cheese can be influenced by a mixture of one or all of these.
Cheese comes from milk. Milk comes from livestock, and livestock produce milk from their feed. The feed (be it grass or silage or other) can have a huge effect on the colour of the cheese. This happens through its own natural colour compounds (chromophores), or other components (fats).