Encontre algo interesante para compartir ya que busque sobre el tema en internet, casi todo vuela sobre la misma respuestas:
Y se podria resumir en :
Si el color influye en la disipacion, pero no en el espectro visible, sino que se busca un negro en el infrarojo.
El color negro influiria en la disipacion por radiacion que en el caso de un disipador es un %10 , ya que la mayoria del calor se va a por conveccion.
La pintura para los disipadores tiene que ser especial, cualquier pintura solo lo haria peor. O anodizados.
Con respecto a la placa, no veo mucho beneficio el color, por que es un pedazo de aislante. Con la superficie que tiene pienso que tambien la mayor disipacion debe ser por conveccion ( por el aire que circula ) y de disipar el calor terminaria siendo por el cobre que es mucho mejor conductor que por la placa.
Black does radiate better than other colors. I remember doing experiments on this in my undergrad degree. However color is not the only concern here. Paint usually is a poor heat conductor (especially household paints, this is why there are special heat sink paints), especially compared to metals, and therefore painting a heat sink using regular paints actually hinder heat dissipation. You enhance radiative dissipation (due to blackbody radiation), but hamper convective dissipation (due to air flow). Using very thin layers of paint means you get the full benefits of having a black color, and minimizes that harm you do to convective dissipation. I hope that clarifies.
I think the websites are saying other things equal black is better, which of course makes sense since black radiates more (although what matters is being black in the infrared, which is far from the same thing as being visibly black). But if the way you get it to be black is by adding a layer of paint that harms the thermal conductivity, it's not worth it; radiation is usually a very small proportion of heat transfer. The radiationsink website is basically saying that in natural convection heat sinks, radiation is a small (~10%)
Y lo mas importante:
Do not paint a heat sink. Most heat sinks are anodized aluminum. Painting a heat sink
(especially if it's a thick coat of paint) is like putting a blanket on the amplifier.
If you absolutely must paint the heat sink, use the lightest, thinnest coat of paint possible.