Grey's my favourite colour, actually. Nobody likes grey.
Also, you spell it Grey! Brilliant!
Anyhoo, on with the poem. I like the whole desolate theme, and the imagery, and I know you're trying to get your point across when you say grey a lot (or at least it seems so, which is good) however you went a little overboard with how many times you said it, it gets a little too reptitive and the emphasis is lost a little.
Nonetheless, I love the imagery, and it's pleasant on the eyes and on the reading.