I saw a little snippet on youtube re: that. What colour should the sky be with an SO2 atmos?
(Or is it a simple case of shorter blue wavelengths tending to scatter back - off most molecules eg. CO2 roughly equivalent to SO2 size wise - and vapours/clouds are more likely to be odd hues??)
I looked it up, it's a colourless gas, depends on the size of the molecule and the scattering effect but I am guessing much the same as an Oxygen atmosphere, I thought myself it might be yellow with the sulpher, but the dioxide bit makes a lot of difference. Oh yes trace amounts would smell awful so I am guessing most of the inside areas of those stations would pong a bit.