I stumbled upon this technique while using up leftover paint, but it's so cool (and easy!) I thought I'd share it here.
I started by painting dioxazine purple fluid acrylic onto a piece of white cardstock. Oh,and from here on, assume all fluid acrylics are mixed about 50/50 with acrylic glazing liquid.
After it was dry, I sprayed it with several colors of Ranger Adirondack Colorwash until it was pretty wet. It ends up pretty dark, and it's hard to get a good photo of it.
Here are the colors I used, but you could probably use whatever you have, as they mix together to form varying shades of brown.
Then I clipped the papers to let them drip and dry:
Once this layer was dry, I sponged on fluid acrylic in irridescent gold:
After that, while the gold was still a bit wet, I added Quinacridone Crimson to the gold and sponged that on, giving it a coppery look:
Here are the exact paints I used:
And here is the result. The first two photos are taken in my studio, and the last is a scan of one of the pages, which really doesn't show the metallic quality of the paper. I apologize for the quality of these photos!