VEVOR 4x4 Post Base 4Pcs, Internal 3.6"x3.6" Heavy Duty Powder-Coated Steel Post Bracket Fit for Standard Wood Post Anchor, Decking Post Base for Deck Porch Handrail Railing Support

I would think, yes. Paint with a 'shake can'. It may be prone to chipping over time; that's a problem because of having to remove them to be repainted. Maybe masking tape around the wooden post will solve that problem...?

I did not paint them, but you could. They have a satin-like black finish. Recommend a primer, then paint.