Paint or gel stain are probably your best bets! :)
You can use chalk paint to transform your set! Make sure you finish with an accompanying chalk paint wax or clear finish. I would chose Annie Sloan paint for an entire set because I feel it will give you the best finish for long term, wear. start with one quart-you will be surprised how far one quart will go! Annie Sloan is a bit more expensive but if you want your set to last for years try it!
You could paint it. If it is intricate, it might be hard to sand so chalk paint would be easiest.
Tammie: maybe this will help
Your end product depends on the prep!!!!!! I know many say that doesn't matter with certain paints....but believe me if you want it to look professional it matters!!!! If you are just going to paint again, you could sand it smooth and primer it. Then I would steel wool or lightly sand again before you add your paint coats to get that super smooth finish. Since it is oak you may want to fill the grain. Use a product like this to fill the oak grain: https://www.amazon.com/Aqua-Coat-Cabinet-Filler-Environmentally/dp/B07HQY2PF6/ref=sr_1_fkmrnull_1?crid=20Q1AHZZ9XLBN&keywords=aqua+coat+grain+filler+cabinet&qid=1556719316&s=gateway&sprefix=aqua+coat+g%2Caps%2C122&sr=8-1-fkmrnull
Check out this video on that.
How To Fill Grain In Wood. OAK Kitchen Cabinet Makeover. - YouTubehttps://www.youtube.com/watch?v=3iserH1H_rw
I know this says for oak kitchen cabinets, but you will see what I mean when you start sanding oak. It doesn't matter what it is, OAK has a large grain! After painting you can seal your project so it won't chip. Good luck!
Paint as many have suggested or stain a dark color like ebony or java. If it is in good shape, you might be able to go short of a full refinish and scuff with steel wool then clean. Now it's ready for a new finish. Make sure to remove all the hardware. it can also be updated with spray paint. I went silver on a pair thrift store night stands because I couldn't see paying $300/each for them. They had an outdated finish but were in good shape so I did the scuff, clean, prime, & paint. I used RustOleum Metallic and spray paint for the pulls.
I would paint it in a neutral color such as white, it seems lighter colors are all the rage for furniture these days.
Scroll through these photos until you see something you like. There are so many great bedroom ideas here on how to makeover furniture:
Here's a post that might help you - https://www.confessionsofaserialdiyer.com/the-rest-of-the-oak-bedroom-set/
Use chalk paint to lighten it up. A lighter color will make it look more modern.
Here's a good idea: https://www.youtube.com/watch?v=iJq01fBVhPQ