The aqueous solution of ${\mathrm{CuCrO}}_4$ is green because it contains:

Because of the blue ${\mathrm{Cu}}^{2+}$ ions and the yellow ${\mathrm{CrO}}_4^{2-}$ ions, the aqueous solution of CuCrO4 is green.

${\mathrm{Cu}}^{2+}$ ions are blue in an aqueous media, while ${\mathrm{CrO}}_4^{2-}$ ions are yellow, resulting in a green ${\mathrm{CrO}}_4^{2-}$ solution. Green colour is obtained when the colours blue and yellow are combined.