Well if it's anything like the pictures on line it's getting back towards the discontinued Orkney Grey - with perhaps a bit more silver metallic in the mix - lighter than the current greys but a bit darker than the Indus Silver.
As you say though, difficult to judge without seeing one in the metal, it may have a tint to it that doesn't come over on screen.
Plenty of comments about this colour on the Velar forums, apparently it's a bit ice green in normal light (based on seeing this at the launch and on other Evoques at the dealers), the configurator makes it look like it has a bronze tone.
When you can try to see the colour you might want at a dealers.
Went through Heswall on the Wirral to-day at about 1300hrs, parked at the side of the road was a Lady Penelope Pink (mat) Range Rover Evoque. Must of been a custom job, not seen anything like it in Evoque form before.