Colour Picker

This is a colour picker from a client project that I'm working on at the moment. It's a bible app, but I cant say much more about it for the moment. In essence, as the user drags picker around the colour palette, the colour in the blue tile below will change in line with this.

The user would then press the 'ok' check button to the right and the dark grey note section would slide up to hide the colour picker.

Thoughts and comments are welcome.

Cheers