Check a tiny piece with a knife, if they were painted, then the paint will scratch off… if stained it will not (unless you really go deep into the wood) … if stained and varnished, then the varnish will also scratch off but will be a more flaky looking residue… so …to paint them you should prime them first using an oil base sealer-primer (or use a pigmented shellac sealer primer… which will dry much faster) … then paint with one heavy coat of Sherwin Williams paint (use a semi gloss finish on woodwork… color of choice) … See my site on this here: http://www.Paintahouse.com
Good Luck!