I remembered reading a few threads on the differences in color between shadow and steel. Here's a side by side picture for comparison purposes.
Steel IMHO has mauve/beige undertones, while shadow has a hint of olive within gray... both colors are such chameleons when mixed with the outfit you choose to wear. Steel becomes more beige/less mauve when paired with something brown, and shadow becomes less olive/more gray when paired with gray outfits. They're such fun colors to play with!