Variegated shrub "gold" leaf and stem problem

Just noticed that one of my variegated shrubs (can't remember the name unfortunately) has a gold coating all over the stems and leaves and the leaves themselves have lots of little black spots on them.

Does anyone have an idea of what has caused this and how I get rid of it. 

I started to spray with a fungicide and thought that some of the leaves looked less "gold" in colour but I would probably need lots of bottles of fungicide to get rid of the amount on the shrub. I can literally scrape the gold coating off the leaves and stems. It is due for trimming but would this help?