3dRose makes a few versions of cover plates for light switches and outlets.
They fit right on standard toggle switches or outlets. Just unscrew the old ones and screw these on.
Here is a different version of the Blue Willow Plate pattern used for cover plates.
You can get metal Blue Willow Pattern switch cover plates made by Jessies Design Industries. I can’t find that they have outlet covers.
3dRose also makes Willow pattern switch plate covers in Teal or Brown versions, too.
I was only able to find one Blue Willow pattern plate that will fit decora switches and outlets. It is made by Gotham Décor. It is enameled onto metal. They make the same pattern on toggle switch covers and outlet covers.