Color sharing

[drewyoungren]

Although color for each graph object is mostly cosmetic, it could make sense to push it out in a scene (or poll) as a way to differentiate different objects of the same species in a scene.
I took it out of params (perhaps prematurely). In any case, makeObject and the message passing should support it, I think.
Would hear other opinions.

[Evan-CTL]

I see no reason why it should't be included in the broadcast message