I saw some new duochrome polishes and I think I have all the colour shifts which were there. All except the light blue / light purple pearlescent duochrome, similar to Models Own - Indian Ocean, which I don't think I would realistically wear.
The others by Rimmel are:
Royal Blue - Light blue / light purple
God Save - Chocolaty metal / copper
Pearly Queen - Pearl / baby pink
Now on to what you came for, Purple Reign!
Opaicity: Thee coats
Colour: Flits between red, purple and slightly blue