Here is a new to me watercolor tool from Faber-Castell called”Albrecht Durer Watercolor Markers". The markers can be purchased as singles or in set from Dick Blick, with the best deal being in a set.
The two horse sketches were done by using a line technique and also putting down areas of color and then using a damp watercolor brush to lighten or blend the areas. You have about 5 minutes to play with added color. I seems like a fine sketching medium. The examples are on sketch paper and I think that watercolor paper would give you more working time before rumpling occurs.
