This is Little Greene's 'Dash of Soot', it's a lovely soft warm grey with hint of lilac. What sort of blues have you in your dressing room? I ask only because dash of soot is actually quite tricky to colour scheme with. The only blue it works really well with, in my opinion, is a very dark and strong colour like Farrow and Ball Railings.
If you can let me know the blues I'll have a think about what would work best. I think you're right about cornforth blue, you want something to warm your scheme up. I can see why you're drawn to this colour.

*cornforth white