How do I update frames on paintings economically?

I've spray painted frames before - works like a charm!

Protect the paintings in a way that won't damage them, then paint the frames. I've had great success using chalk paint and a topcoat on frames I've updated. Pick a type of paint that complements you painting and decor.

I would take the paintings out then use Rustoleum paint, it comes in a wonderful variety of colors. I have done this many times.

Rinhave an expensive oil painting in a Gold frame. I wanted it silver. So I used a decoupage glue and also used silver leaf then, antiqued it using a black paint. Turned out beautiful! To protect the painting, I covered it with brown paper and taped it down.