Shader coding is a very specific field in itself often with its own quirky languages and requirements, you'd usually have a specific programmer or TD for that job. I wouldn't imagine it's common for any artist to need to know shader code for employment, although it's a very good skill to have - most engines will have…
There are 2 ways right now, either wait for unity 5, or get shader forge for unity or maybe one of the other shader packs, unless you want to write code in HLSL The default shaders are unusable
Writing shader code to work in Unity is also a complete and utter ball-ache. Buying Shader Forge is probably the only reasonable option. ..or use a different engine with fewer annoying hoops.
You can give this a try http://pastebin.com/61umeU4r just make a new shader in the project window, open it in monodevelop by doubleclicking and paste this over the existing code with this. The legacy shaders were built mainly for performance - this particular use-case really highlighting the worst of the concept by having…