Halloween // How to paint porous pink foam to look like spam/meat? Making dog costume--see pics pls

I'm making a costume for a Hawaiian-themed dog contest and found an adorable spam musubi (spam "sushi") outfit that has basically gone viral. I've got all the materials: white tshirt, packing peanuts (rice), greenish-black felt (nori/seaweed), and a piece of pink foam. But I'm not certain how to "weather" the pink foam to give it that "meaty spam" authenticity, and was wondering if anyone had any ideas.

I have read that the foam is porous and needs to be sealed; this can be done with a 1:1 ratio of wood (or Elmer's) glue to water. I'm still not certain on how to make it look semi realistic--dark wax? Not really good at anything that requires freehand talents, but I'm an ace with spray paint!

Not surprisingly given how viral this appears to be, the OP hasn't gotten back to me about how he/she pulled it off, so thought I'd give it to you all to see if there were any ideas.