The motivation for this question comes directly from this thread. The proposition is that the color of something changes how fast it cools (note: specifically the rate of cooling, not taking into account the change in heat absorption). For example: would adding black food coloring to an otherwise light-colored fluid, make it cool faster? The proposed explanation for such an effect is that the fluid becomes a 'better' black body. Is this true? Why or why not?
My current thinking:
The 'color', per se, has no effect on the rate of cooling. For two bodies at the same temperature, any difference in color is due to it's reflection properties, not its emission properties - which will be identical, because they have the same temperature.