Is the surface of TrES-2b actually dark? The exoplanet TrES-2b is known as the darkest planet ever found, reflecting &lt;1% of the light that hits it.

What does it mean in respect to the surface? What would we see below the atmosphere of this planet? Is it a "shadow planet" with an atmosphere so thick and dense that it blocks all light that would reach the surface?
I don't know, how it works there, but perhaps it is easier to imagine, how it could look. 

TrES-2b is a gas giant, so it doesn't have a well defined surface. When you are somewhere in the atmosphere then:

-When looking up, you will see the light, as deep sea creatures do. The amount of light and its color will depend on how deep you are.

-When looking down, it should be dark (black), comparing to how it looks up. Otherwise, the atmosphere would be reflecting light.

-When looking to the sides, it should also be dark, for if the light were scattered at some angles, it would also be scattered upwards.

So, one simplest possible model is: like in deep sea.

Note, that at some other wavelengths, particularly in infrared, it all can look very differently.