I posted the Boots haul earlier showing these, managed to swatch them tonight. All polishes are quite "brush-strokey."
Firstly the "underwear" for the swatches: I used a base of a-england Camelot on my index finger, Excalibur on my middle finger and just base coat on my little finger for all of these. My ring finger I varied according to the Rimmel I was wearing.
First one is Pearly Queen, soft lilac to green it certainly is very much like OPI's Significant Other Colour on the nail. On my ring finger I used a-england Guinevere.
I really like this over Guinevere, over black the green is very dominant. I don't like this one alone.
Next is Gold Saved the Queen, on my ring finger here I used China Glaze Agro.
No major differences here between them, I think I would probably pair this with black though if I wear it again (not sure I will though as the gold is quite strong and not my favourite of colours.)
Finally is Royal Blue, I used a-england Elaine under this. I also used Essence Where is the Party on my thumb for a comparison.
When applied over black or plum this one certainly is very similar to Where is the Party. I really like this over black.