Cobalt Green Deep [PG26—Cobalt Green Deep] Old Holland Classic Artists/ Watercolors, 6ml tube. $12.59 at Blick. "This pigment offers a deep but dull and opaque tone of Cobalt Green. It has moderate covering power, but low tinting strength. It is primarily for use on its own, or for mixing with other cobalt colors. It is an alternative to cobalt(II) zinc oxide, another form of Cobalt Green."