It won't matter. This isn't the technical explanation but you'll get the idea.
A specified material will only move heat through and away or into something else at a certain rate. Some grade of steel will allow heat to travel through it at a different rate then say, aluminum. You can get the technical explanation on heat transfer and coefficients from a physics forum.
Bottom line-A light coat of engine style paint won't slow it down.
Notice that I answered without using the terms conduct, radiate...