Hair is sacred to Sikhs. While debates do go on as to whether it’s acceptable to cut your hair, as the CBC explores, it remains quite clear that kesh dictates that hair should remain long, and that was clearly laid out by Guru Gobind Singh when he was expanding and settling on the Guru Granth Sahib. What’s less clear within the discussion is whether hair can or cannot be tampered with - colored, styled, and so on. There are strong arguments in either direction, however, and it really comes down to each individual Sikh as to whether they feel it’s a good idea or not.
Arguments for
Sikhs are part of the wider world around them, and many of the core tenets of Sikhism tie into being in tune with the global society at large. Hair coloring is of course very popular around the world; with up to 85% of the world having black hair, it can be exciting to pick a different color and buck the trend. As for prohibition within Sikhism, there has been one interesting bit of precedent. In 2014, the Shiromani Gurdwara Parbandhak Committee barred women from dying their hair - but only if they were performing kirtan at Gurdwara Santokhsar Sahib. There’s an implication here that dying hair can be fine on a personal basis, and is a personal choice - but at the highest and most reverent levels, may result in refusal of access to certain activities at Gurdwara.
The argument against
The argument against dying hair is quite clear; it is prohibited in the Man-mat to tamper with hair, whether through hair cutting, trimming, other forms of removal or, indeed, dying. It’s worth noting, however, that not all Sikhs adhere to every single restriction - just as in many other religions. However, there is clear precedent in Sikh scriptures that tampering with hair in any sort of manner. Accordingly, from that perspective, it’s absolutely justifiable not to color the hair and to take a hard line against it.
Acting pragmatically
The Sikh Dharma International has clear teachings on the idea of self. Praying to heaven is actually about challenging yourself and praying to the good inside of you; happiness is as much about virtue as knowing yourself and being happy. External appearances shouldn’t really matter, but, at the same time, the color of your hair is superfluous, and like wearing clothes that are comfortable and feel good to wear, it can create overall wellbeing. There are more important tracts of thought within Sikhism that are above hair color, and so it really does come down to a matter of absolute personal choice.
Does Sikhism preclude hair coloring? Strictly speaking, yes. Does that mean that no Sikh has ever dyed their hair, for a bit of color or for any other reason? Of course not. Ultimately, coloring hair is a personal choice that Sikhs can undertake, and, in turn, reconcile with their own beliefs.