I know this horse's carcass has been pounded harder than Neil Peart's drum kit after a 3 hour solo, but things obviously need to be clarified.
Here's the Topps 'orange' background...
1973orange81.jpg
Here's the Topps 'natural' or 'trees in background' version...
1973natural81.jpg
And depending on how crazy into variations you wanna get, here's the Topps 'pink' background (it could be argued that this one is simply the result of the color balance and is not truly a different version of the card)...
1973pink81.jpg