So I've had the odd experience of learning that The Iron Dragon's Daughter (the first book of the stand-alone trilogy, not to be confused with The Iron Dragon's Mother, the last) leads off a list on The Portalist titled "Gritty and Gray: 12 of the Greatest Grimdark Fantasy Books Ever."
On the one hand I'm gratified to be on the list. On the other, I don't personally think the Iron Dragon books are so grim and dark as to be defined by that term. There's a lot of joy to be found in them too. But of course, that's not my call. A novel is like a bird. For the longest time you fill its gaping maw with the creamed worms of your imagination. Then one day it wobbles to the edge of the nest, spreads its wings and takes an awkward leap... and is published.
From then on, its roosts where it wills. The writer's authority over it is no more. It belongs to the readers now.
Let them make of it what they will.
You can find the list here, by the way.