How to repaint resin garden ornaments ?

Yes you can. Concrete, resin, plastic.

https://www.hometalk.com/search/posts?filter=paint%20resin%20statues

Yes, here's a helpful link:

Resin and Plastic

Faded resin or plastic ornaments tend to peel if you try painting them, but taking some time to prepare them first may improve your chances for success. Most resin ornaments were infused with dye during casting so the paint wasn't applied to the surface. Scrub the ornament with a cleaner containing trisodium phosphate to remove stains, dirt and mildew, which prepares the surface for painting. An oil-based spray paint formulated for outdoor use on plastic and resins works best. Apply the paint in two or three thin, even coats, allowing each coat to dry completely before applying the next. If you are using multiple colors, tape off areas you don't want to paint first. Resin and plastic ornaments often need repainting every two to three years.

ref:https://www.hunker.com/13404408/how-to-repaint-yard-ornaments

If you do, you will probably need to seal it because I think it will fade quickly.