New Delhi, April 19 -- How blue is Krishna? The poet can get away by responding with a metaphor, calling the dark god Ghanashyam, a storm cloud. Krishna, passionate lover, desired by many and desiring many, is the dark cloud, writes the poet, about to descend on the beloved, likened implicitly to the thirsty chataka bird. The word "Krishna" itself means dark, and he is also called "Shyam", which covers a range of darkness, from blue black to grey, with much in between, even the green of the tenderest grass.

The painter, however, working within the conventions of traditional Indian art, has to put colour on form. What goes into the making of Krishna's blues on paper or palm leaf? Into the colour of a storm cloud? A 17th-century Pahari min...