Arnold isn’t that difficult to learn, but you had better start. Since the release of Maya 2017, mental ray is out, and Arnold is in. If you are going to be using Arnold, you should get the free alShaders for it.
Some of use (like myself), need to get oriented in how Arnold works within Maya. Thankfully, Lighting TD Arvid Schneider, has been posting his 100-level course quick-start guide, helping artists make the dive into the amazing Arnold Renderer.
Here, Arvid shows off the power you can have at your fingertips using the alShaders utility nodes.
alShaders is Anders Langlands’ open source and free physically plausible shader library for Arnold, that is focused on offering tools for production.
alShaders has a long list of utility nodes that can be used in all kinds of workflows. These include, Combine Color, Layer Color, Remap Color, Switch Color (and float utility nodes for each of those), Cache, Jitter Color, Input Vector, and Input Scalar.
Arvid also provides a little demonstration for using alJitterColor, which can allow you to instantly get color variation across multiple objects, easily.