Asking about fiberglass bows in here is kinda like ording a ham sandwich at a good Jewish deli.
How about a cheap roll of camoflage duct tape?
Or go to the kitchen department of the hardware store and buying some of that adhesive backed plastic that you line drawers and shelves....pick the woodgrain stuff and use that?
Ok, how about buying a 12 pack of your favorite bottled adult beverage of choice and soaking off the labels and applying those to the back of the bow. Actually, that would look kinda cool, there are some really neat labels on some of the microbrews out there.
But for the snake skin option, a lot of guys here have been posting bows they have backed with the snakeskin fabric purchased from the PA advertiser, 3Rivers. They sell a rattlenake pattern as well as a really nice copperhead. I imagine you would want to scuff the effing-glass with sandpaper, wash with acetone to prep. Mix two part epoxy that you get in the hardware store in the double syringes, cut it 50/50 with some more of that acetone. Paint the back of the bow, stretch the fabric across, and wet scrape with a rubber spatula and more epoxy/acetone mix to lay it down tight. Kinda like laying up another layer of effing-glass. Sand with finer and finer grit until you get the smoothness you desire and a last layer of epoxy/acetone cut with 75% acetone applied with a smooth brush.
And as always, post your pics!