It's well-established in physics that black or dark-colored objects radiate heat faster and more effectively than light-colored objects.
So, in almost every building that uses steam heat, why are the radiators painted silver or some other very light color?
A salesman from Runtal North America, Inc. (http://www.runtalnorthamerica.com) contradicts your solution a bit:
"Runtal radiators heat a room by both radiant and convective heat transfer. Panels with no fins are about 40% radiant and 60% convective, while triple finned double panels are about 15% radiant and 85% convective.
The ratio of radiant vs. convective heat output for a given radiator is also affected by the radiator's surface temperature (which is itself determined by how hot of water you run through the radiator). The cooler the surface temperature, the greater the radiant percentage is, and the less the convective percentage is. But you also have to keep in mind that the cooler the surface temperature, the lower total output of the radiator too. So, there are many variables to radiant vs. convective.
But back to color, I state again that there is no sugnificant difference in output for different radiator colors."
A Contradiction
