How does the colour of K2Cr2O7 solution depends on pH of the solution?

• K₂Cr₂O₇ is a strong oxidizing agent, which itself gets reduced and oxidizes other compounds. It is orange in color.

Cr₂O₇^-2+H₂O ----------> 2CrO₄^-2+2H⁺

• pH <7- Solution is acidic - Orange to yellow due to yellow color of CrO₄^-2
• pH >7- Solution is basic - Yellow to Orange.