Select the coloured compound(s):

An important molecule employed as an oxidant in numerous processes is potassium dichromate (${\mathrm{K}}_2{\mathrm{Cr}}_2{\mathrm{O}}_7$), an orange-colored crystal.

The pentahydrate of copper (2+) sulphate ${\mathrm{CuSO}}_4\cdot 5{\mathrm{H}}_2\mathrm{O}$ is copper (II) sulphate. a solid crystal that is vivid blue.

Tetrammine copper (II) sulphate $\left[\mathrm{Cu}{\left({\mathrm{NH}}_3\right)}_4\right]{\mathrm{SO}}_4$ is blue in colour.

Therefore, all the options are correct.