${\mathrm{CuCl}}_2$ dissolve in water & give blue coloured solutions

${\mathrm{CuCl}}_2 + {\mathrm{nH}}_2\mathrm{O} \to {\mathrm{Cu}}^{2+} \left(\mathrm{aq}\right)$

$\mathrm{AgCl}$ not soluble in water.
${\mathrm{Cu}}_2{\mathrm{Cl}}_2$ is not soluble in water.
${\mathrm{ZnCl}}_2$ is soluble but colourless.

${\mathrm{ZnCl}}_2 + {\mathrm{nH}}_2\mathrm{O} \to {\mathrm{Zn}}^{2+} ( \mathrm{aq} )$colourless