Painting - Painting suspended ceiling grid

I have an older home with a suspended ceiling that I would like to paint to freshen up the room. The tiles look like no problem to paint but I curious on how to clean then paint the metal grid. What kind of paint? Brushing may leave marks, are there alternatives? Any help would be appreciated.

Roll or spray the tiles. The metal grid is spray or brush. The brush marks from a top quality paint and brush will not be noticeable, once the new color covers. Remember how difficult it is to look at the grid in the first place?

Dust the tiles, then prime, then paint. Wash the grid with spic and span or such. If the color change is great or the grid's paint is in bad shape, priming it also might be in order.

Flat paint on the tiles, semi-gloss on the metal grid.

Hope this helps.

Prime the grid first. The primer forms a better bond.
I'd also prime the tiles. The tiles will probably soak up quite a bit of paint and the primer is less expensive and forms a better bond.