Balata is a hard rubberlike material that is gotten from drying out the juice from the bully tree. It is pronounced Ba*la*ta.

vulcanisation - vulcanization: process of treating rubber or rubberlike materials with sulphur at great heat to improve elasticity and strength or to harden them

In the early part of the 20th century the word vulcanizing was mostly used in association with patching inter tubes, later glues became more popular and eventually replaced the heat in securing patches on the tube.

Silicon is an element. It is not usually found as silicon but as a compound that makes up quartz.
There is often a confusion with silicone which is a synthetic substance made up of silicon, oxygen and other elements, mostly carbon and hydrogen. Silicone is generally a liquid or a flexible, rubberlike plastic and it is often used in shampoo.

Crocodiles have a body covering of scaly skin. All reptiles have scaly skin. They do not have individual scales like fish do.

This tough, scaly skin is called scute or osteoderms.

The simple answer is, "just like you would paint anything else." However, to my knowledge, mudguards are made of rubber, or a rubberlike, material, and most paints will not last very long before beginning to fall off. The only thing I can think of that MIGHT stick, fairly permanently, are the type of paints used on the plastic/rubber "bumpers" on later model automobiles. This type of paint is probably NOT available at your local auto parts store, so you would have to get it at a paint store that sold automotive paints. Also, someone at one of these stores, would probably know what, if anything, would work successfully. Good luck !