Something like this. Probably some kind of noise mask with some metallic, low roughness?
$\begingroup$ Related : blender.stackexchange.com/a/105302/29586 $\endgroup$– Rich SedmanAug 25, 2018 at 9:18
A good way to approach a glittery material that I've found works well is using voronoi cell noise as an input for a normal map:
By changing the strength of the normal map, you can change how non-flat the glitter effect is, and the size with the Voronoi scale.
If the object will be moving or animated, it would be recommended to plug a UV Map Node into the Voronoi Texture
Here's an example node setup with some basic blending via vertex color:
This method also works great for snow, car paint, and anything else that has a glitter to it!