heat absorption and emission

Yes, there is no differentiation between absorption and emission of radiation. The principle is decribed by Stefan's Law.

The Law states that the radiation emitted or that absorbed by a black body is propotional to the fourth power of the absolute temperature. Be aware that in the case of sbsorption, the temperature refers to in the Law is the temperature of the object giving out the radiaion.

For objects that are not black body, an emissivity is introduced. In general, black coloured objects have higher emissivity than white coloured objects. Thus black coloured objects emit/absorb thermal radiation better than white coloured objects under the same environmental condition.

The wikipedia gives a good account of Stefan' Law, you may wish to make reference to it,

http://en.wikipedia.org/wiki/Stefan%E2%80%93Boltzmann_law