Rayleigh-Benard-convection at high aspect ratio

A Direct Numerical Simulation of Rayleigh-Benard-convection.
A fluid of initially uniform temperature is heated from below and cooled from above. Blue = hot fluid, red = cold fluid.
The aspect ratio of width to height of the system is four.
Visualization using Voreen www.voreen.org/

[@TheLivirus]

"Blue = hot fluid, red = cold fluid."
I think you mean the opposite.