If those plastic handes are smooth, and/or shiny, I recommend a light steel wool to remove any glossy finish. Try a '00' or '000' steel wool first. Take some time to prep them, and make sure you wipe them free of dust before spraying.
Then get a good spray paint and spray them. Spray lightly the first time, let 'em dry, then hit 'em again, and then a third time.
Don't try and spray them once and done. And make sure you let them dry good between coats.
That's what I'd do. And I've stained and painted a lot of stuff over the years.
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