What is the ruling on hair highlights (mesh) and hair dye (ṣibghah), and what is the difference between them? Do both prevent water from reaching for ablution? And is it permissible to use them for adornment, or should they be avoided to stay clear of doubts?

The ruling on dyeing with highlights was previously addressed in Fatwa no. 36437. There is no difference between it and regular hair dye, provided that it is not black, and does not involve deception, misrepresentation, or imitation of disbelieving women. If highlights or dye are free from what makes them unlawful, then there is no difference between using them and not using them. There is no doubt to warrant saying that refraining from them is preferable.