ok very easy science for you guys:
black (or anything dark for that matter) is influenced very quickly to temperature changes in its surroundings. This means it heats up very quickly, but will also lose its heat quickly.
Polished surfaces (or anything of light color) take longer to be influenced by the temperatures in its surroundings. This means it heats up more slowly, but retains the heat for much longer.
Homework for tonight class:
Get 2 ice Popsicles . put 1 in aluminum foil, and 1 in for instance a dark trash bag.
The one in the bag will melt much faster.
Class dismissed