[Interest] Toolbar size and icon color

[Sensei]

Dear all,

I'd like to create a toolbar for a main window, customizing it. However, 
using setIconSize isn't affecting the toolbar size or the icons in it.

Am I trying hopelessly?

Another related topic is this: is it possible to use black icons?

The reason I'm asking this possibly naive question is that when clicked, 
icons are grayed out. Using black icons means no visible action is taken 
when they're clicked.

Is it possible to "whiten" them on mouse clicks?

Cheers!