Been playing and during my experimentation - I came up with this material - thought i’d share:
Basically - its a black glossy material with coloured sparkles in it which colour shift as you move around the objects. I have made the sparkles quite large in the image just so you can see them properly - but of course you could make them much smaller.
You can make the sparkles any colours you like by changing the color ramp with the RGB bands in it. Also - if you change the position of the black/white colour ramp - this will increase/decrease the total number of sparkles. Changing the voronoi texture scale will make the sparkles larger or smaller.
It really comes into its own when animated - stills don’t do it justice.
Here is the node setup