Shades of Grey is a great book...and no I haven't got that wrong. I mean Shades of Grey by Jasper Fforde. A book that makes you think, and laugh.
Between Shades of Grey is a very moving book. It's by Ruta Sepetys and made me cry in places.
I'm only a quarter of the way through 50 Shades of Grey by E L James, and yes, I might be reading it, but can't say it is as griping as the other two that share part of the name.