hi, you have been using kojic acid
for acne scars
. it is useful in post inflamatory hyperpigmentation
which occurs as acne heals. you have not mentioned whether your colour has become darker or lighter.
Kojic acid is a skin lightening agent. skin can be darker in case kojic cream has not suited you and caused irritation and redness
.so stop using it .it might help to get your colour back.
in case you feel that your colour has gone lighter. u will regain it once you stop using it in a month or so.
niltan again is used for post acne pigmentation and can be used. but you need to use these creams for longer durations for satisfactory results,.
you can enhance the process by adding peeling and microdermabrasion
avoid picking and squeezing acne as it increases the chance of pigmentation and scarring.
hope this adresses your concern.