Using hair dye for employment reasons

Is hair or beard dyeing permissible only for job purposes which is advised by an employer? It is a customer service sales job. The employer advised me to colour my hair and beard black to show that I am younger because markets like young energetic people. It is a garments label industry. Here, colouring the hair or beard black (to show that I am young) will not cheat people. It is only to show that the company has appointed smart officials. There is no cheating in the product. Product quality will remain ok as per company policy. I need a ruling in this regard.