Is heat RADIATED better by darker colors?

Understand...heat is not radiated. Photons are radiated...and absorbed.

Heat is the average kinetic energy of the atoms and molecules of the object that has the heat. So nothing is hot until its atoms and molecules say its hot.

Black, one of the darker "colors," is black because it is a weak radiator of photons. So that means, whatever photons are released and radiated will not be a lot and will not heat up whatever they strike very much.

Another way to see this is that black retains that energy from the photons. Which is why it's black...duh. So very little escapes as generated photons to cause heat elsewhere.

No... it is absorb and reflect... that is why most heaters are white, silver or tan... they reflect heat... black absorbs it and makes it less effective.