It is unlawful to apply black dye. The other colours other than black like henna etc are lawful. In khidhab, the hair should be only dyed, if the hair gets a layer of colour (as in paints) preventing water to reach to the hair then it is unlawful and in this case wudhu and ghusl will not be valid.
(2) What are the works assigned to the employee in excise department or in bank? What are the other ways from which the bank and excise employee gets income other than salary? Please, explain it, then in-shaAllah you will be replied.
(3) It is unlawful and haram to take loan (on interest) from bank and pay interest to the bank, but the amount of loan shall not be regarded haram. However, attending the feast of debtor and one who takes loan on interest is makrooh.
Allah (Subhana Wa Ta’ala) knows Best
Darul Uloom Deoband