Actually there is a practical aspect to the silver finish.
In the past, people liked black film bodies because they were black chromed over a brass top and bottom plates. Very seasoned bodies would show brassing at the edges where the chrome was worn down. Black bodies were more expensive because of the black chrome and looked cool.
Then polycarbonate plastic came along and camera makers opted for it because it was cheaper, easier to mold, and it didn't look so bad in black and no more worn edges.
Now back full circle and we have a magnesium covered body. Now if you sway sway scratch your black K-5, you'll find the color of the magnesium base is a light grey, pretty obvious on black, but now with silver you'll be hard pressed to find where the scratches are. Plus a silver body is a lot cooler if your camera is sitting under the sun.