There is a bunch of natural ways to add highlights to dark brown hair boy can try at home. So, apply to random strands one of the following:
1. Chamomile tea rinse.
2. Henna powder mixed with boiling water.
3. Vinegar diluted with distilled water.
4. Peroxide and water solution.
5. Cinnamon paste, made of cinnamon powder and hair conditioner.
6. Salt dissolved in warm water.