Dr. Dalai has posted an interesting article (Dalai's PACS Blog: Show Me Your Worklist!) on colour usage for a PACS worklist.
I think that colours are an important aspect of any worklist system, because they give you a quick overview of what is happening at any one time. I had not previously considered colour in the worklist as a point to look for in my PACS investigations, but now I can see that it is a very useful feature that will assist our radiologists greatly. (Thanks Dr. Dalai!)