As you mention that your penis was white.This may be because of collection of smegma
or candida infection.
Concern is your personal hyagine. Because if it was patch of candida then that will not clean so easily.
Keep good personal hyagine.
You mentione that there is itching,which may cause by both smegma and candida infection
contain cotrimazole which is antifungal .I t will take care of your candida infection if there is ,which is less likely.
Just keep good personal hyagine .TB medicine does not cause whitning of penis.But TB is common in immunocomprimise host and fungal infection
are common in such patient, so consult your doctor.TB medicine eg rifampicine cause orange discolaration of body fluide eg urine even tears.