Is it permissible for a person to object to the increase in a colleague's salary, which resulted in a deduction from this increase, even though the objector's salary is higher?

If the intention was not to harm the colleague, and what he did was to claim what he believes is his right, then there is no blame upon him. However, it would have been better for him not to mention his colleague. But if his intention was to harm him, then he bears the sin for that; because the Prophet, peace and blessings be upon him, said: "There should be no harm nor reciprocating harm," and "None of you truly believes until he loves for his brother what he loves for himself."