The orange colour of K_2 Cr_2 O_7 and purple colour of KMnO_4 is due to

$\displaystyle \mathrm{d} \rightarrow \mathrm{d}$ transitions in both

$\displaystyle \mathrm{d} \rightarrow \mathrm{d}$ transitions in $\displaystyle \mathrm{K}_2 \mathrm{Cr}_2 \mathrm{O}_7$ and charge transfer transitions in $\displaystyle \mathrm{KMnO}_4$.

$\displaystyle \mathrm{d} \rightarrow \mathrm{d}$ transitions in $\displaystyle \mathrm{KMnO}_4$ and charge transfer transitions in $\displaystyle \mathrm{K}_2 \mathrm{Cr}_2 \mathrm{O}_7$.

Charge transfer transition in both.