Can you paint sliding doors and if so what kind of paint can you use?

Are you talking about the frame or the glass itself. The frame can be painted with rustoleum. And the glass, I would suggest window films that can be removed if you want.

https://www.decorativefilm.com/

Sliding doors to the outside? If inside doors, such as closet doors, etc. they can be painted with any good interior paint.

Stained glass paint would give some privacy but let in some light. But for metal frames, I would use Kilz or waterproof Rust-oleum as a primer and paint. ☺️

Yes, we need clarification as to whether these are sliding closet doors, or sliding patio doors. Or barn doors? 🤔

Different internet sites offer colored see-thru vinyl where you can see out but people cannot see in

Yes if you are trying to prevent someone from seeing in, you can get reflective window film that looks like a silvery blue, gold or silver and you can still see outside. It also prevents sun damage and helps keep the house cool. https://www.amazon.com/s/ref=nb_sb_ss_i_3_22?url=search-alias%3Daps&field-keywords=reflective+window+film+mirror+one+way&sprefix=reflective+window+film%2Caps%2C210&crid=1YVN0QOY828

or you can get privacy film that is a frosted white and can have a pattern... https://www.amazon.com/s/ref=nb_sb_noss_1?url=search-alias%3Daps&field-keywords=non+adhesive+privacy+window+film&rh=i%3Aaps%2Ck%3Anon+adhesive+privacy+window+film

If you're looking to paint pocket doors, it's a whole 'nother ballgame! Please clarify what you want to paint.

Depending on what the surface of the doors are, will determine the type of EXTERIOR type paint to purchase. If they are metal (steel) sand lightly to get rid of any dust, etc. now on the doors. Then apply a good primer and then a couple of coats of the color of paint of your choice in an exterior paint. Rustoleum makes good paints to cover metal surfaces. Any good brand of paint for wood might be Behr, Sherwin Williams and others. Good luck! Paint can make a huge difference in the way items look and last.