How to change the color of metal around shower enclosure?

Is there a paint you can 'brush' on instead of spray paint? Seems like that would be easier?

You will want to use an epoxy-based paint on the shower enclosure. Either rent a paint sprayer or purchase cans of spray paint rather than using brushes or rollers, and your choice for finish should be flat or semi-gloss (if you want a shiny finish). While spraying the paint, keep the room well-ventilated, and apply in wide, side-to-side sweeps for even coverage.

Priming prior to painting will ensure that the paint will not come off or crack easily. Use a good quality primer, such as Rust-Oleum Painter’s Touch, which is a multi-purpose primer made for this kind of project. Coat the shower enclosure evenly and give it time to dry.