Yes—if the furniture belongs to you or your building, you can usually repaint urban outdoor furniture when you get bored of the original color. I would not touch public street furniture or anything owned by the city, though, because that can get you in trouble and the finish is often designed to survive heavy use.
The big thing is material. Most urban outdoor furniture is powder-coated metal, wood, concrete, or plastic. If it is powder-coated metal, you can paint over it, but you need to scuff the surface first so the new paint can stick. Sand off any rust, then use a rust-inhibiting primer and an exterior-grade enamel or spray paint made for metal furniture. Thin coats work much better than one heavy coat.
Wood is pretty forgiving. Clean it, sand it, fill cracks, prime it, and then use exterior paint. A clear sealer on top helps if the piece sits in rain or sun all year. Plastic furniture is the fussy one. Some plastics reject paint, so use a bonding primer or a product specifically labeled for plastic furniture. It can still scratch, but it will look better than faded plastic.
Concrete or stone can be painted with masonry paint, but I often prefer a stain or sealer if I want to keep a natural texture.
Before you start, check the rules. If it is your own balcony chair, go for it. If it is shared building furniture or in a community courtyard, ask first. If it is public property, leave it alone.
The actual process is not hard: clean off dirt and grease, sand the surface, repair chips or rust, prime, then paint in thin coats. Do it on a dry, mild day and let it cure fully before using it. A topcoat can help with chipping and fading. When you repaint outdoor furniture, the prep is honestly 80 percent of the result. If you rush it, the color may peel in a few months. If you do it right, it can last for years.
So yes, you can absolutely repaint urban outdoor furniture if you are tired of the original color. Just use exterior paint, match it to the material, and do not skip the boring prep steps. You will save a piece from the landfill and get a color you actually like.