API to dynamicaly change color

[rbaumi]

Describe the feature
Would be nice to have sth like setColor API that will alow user to dynamically set color of the active tool.

[AndrewPixel]

I'd like to second this request and also add to set: alpha and line width.

On my current project the client wants a tool bar on a separate pane. I can hide Painterro's tool bar and I can activate tools from the client's tool bar but I'm stuck trying to set colours etc.