Derwent Watercolour pencils are great to use and you can mix them with water to create interesting colour flows. They're not as bright as Inktense so they're ideal if you like to do more subtle paintings. Of course, you can use them dry and because they have such a soft texture you will find them easy to blend and layer. Watercolour is not permanent like Inktense, so once the colour is dry you can re-wet it and move it about again.
Derwent produces high quality coloured pencils, watercolour pencils, pastel pencils and pastels since 1832. This English company also offers a wide assortiment of accessories for the professional artist.