yes, there is a life display, figure out how to use it. (use wiki EDIT: nvm, it doesn't seem to be on the wiki anymore... i swear it was, anyway, be in debug mode 'd' , and then cycle through displays (clicking button or 'c') or hit shift-1 ). it displays life values in gradients of gray.
a 'dropper' tool will be added, no doubt, and a zoom. Not sure about floodfill for color though.
@roguegeneral--(View Post) erm no, there is no color sampling method currently. Such as middle click/alt click for particles. this same keybind will probably be used to pick existing colors for the decorations.