Ubuntu 15.10 x64 Geforce 580 GTX
Broken: 2.77 official, 2,76b official, 2.75a official
Short description of error
When setting a smoke color in the flow source, the color fetched from the Cycles attribute node is off quite a bit. This might have been the source for the problems artifical3d had with smoke colors in the gooseberry tornado. While the openGL viewport shows the colour correctly, the problem also appears with BI render.
Here you see a comparison of renders with different shaders using the colour from the attribute node and the same colour set directly in the shader:
Viewport OpenGL render:
Volume Scatter + Volume Absorption using colour from attribute node:
Volume Scatter + Volume Absorption with colour set directly in the shader nodes:
Emission using colour from attribute node:
Emission with colour set directly in the shader node:
Exact steps for others to reproduce the error
Bake the sim of the attached file. Connect different shaders in the network with and without taking the color from the attribute node. The color set in the nodes is the same colour as the one set in the smoke flow source.