Hi Louise,
It isn't a monochrome really..it's more of an inversion /negative. All the light bits are dark and vice versa.
What were you trying to achieve? It is ghostly certainly.
Try reversing the negative/inversion and using the Halloween Apps on Piknik to achieve the spookieness.
Remember you can layer things.
Why have they taken the Christmas section away?
On top of what Sharon has suggested I'd be inclined to rotate it a little so the lines of the castle or horizontal or vertical.