I wouldn’t paint any part of the new enclosure. To me, the more natural/organic the better.
What are you planning to build the new cage with?
I only ask because I am thinking of building a bigger cage for my female veiled. Right now she’s in a manufactured 24x24x48. It serves it’s purpose but I know she’d love a bigger cage.
I am thinking pvc pipes, maybe cut in half, window screen, hot glue and the drainage system we have now.
Cheers!