Sophie is a big lover of blue polishes, so of course she has the Russian Navy one. I had a chance to borrow it to compare to the blue that I have, Play 'Til Midnight.
It's a deeper, darker blue, which in two coats looks almost black. The bottle has this beautiful purple shimmer, but you can't see it on the nails.
When I put it on it was difficult to tell Russian Navy from Play 'Til Midnight. They are both deep blue, neither really stand out. And it's really difficult to photograph them so that the differences show. Below in the bottles Russian Navy is to the left and Play 'Til Midnight is on the right.
The only slightly difference I can tell is only in the brightest sunlight - Russian Navy seems just a little bit darker.