To kick off - this is one I did a while ago and donated to a charity auction. It was inspired by a photograph taken on a friend's son at the aquarium. I loved the blue light and the silhouette capturing the little boy's absolute fascination with the moving fish.
The paper was my trusty Bockingford 140 lb which I use for a lot of my small paintings.
Paints: Winsor turqoise, Pthalo Blue and a touch of Quin gold to add a tiny glow here and there.
Enjoy your blues.