Addition of `Cl_(2) to KI solution give its a brown colour but excess of cl_(2) ` turns it colourless. Why?

Explanation

The initial brown colour is due to relase of `I_(2)` from the solution. But excess of chlorine dissolves iodine to form a colourless compound iodic acid.
`Cl_(2)+2KI to 2KCl+ underset(("Brown"))(I_(2))`
`5Cl_(2)+I_(2)+6H_(2)O to 10 HCl + underset(("Colourless"))(2HIO_(3))`