Colour proofing mode is AWESOME!!!

I have to report that I'm very much loving this option (under Canvas in the menu).
I've been working for a British comic anthology and have found it gold for anticipating the appearance of the final printed version.
it doesn't just simulate cmyk but also provides for the slightly off white of paper compared to the glare of a monitor.
I haven't looked into calibrating it to the specific magazine (which has slightly duller bright greens and paler cyans but is virtually identical in nearly every other respect) but I may yet.

An excellent feature. Thanks, development team.