First up, welcome to the forum!
Anodising is a chemical process to protect the parts from corrosion. I note you're in Perth so there are a few options there it looks like.
http://aaep.com.au/
https://en.wikipedia.org/wiki/Anodizing
As you mention there is no option for green from the factory, although they have done the odd special. Doing a one off would likely not be worth their time (except in the case of marketing).
You could ask though, worst they can say is no.
Which leaves the option of rolling your own:
Getting the part could prove tricky, it would really be best to start with a part that was bare metal. Sending them a letter in the post would probably be your best bet.
Another option is paint, sticker, or a skin. With steel you have other options such as electroplating; ie. MV, hard chrome, etc.