Opalescence

This is a secret genjutsu that was once handed down from head of the Hyūga to the next. Eventually, almost anyone with a Byakugan eye could learn this technique, though the head of the Hyūga clan has access to the most powerful version. This is known as the Byakugan version of Tsukuyomi, though the former pales in comparison to the latter.

After activating the Byakugan, the user makes eye contact with their target or touches them. Soon after, the target is thrown into a world where there is only white. Stuck in this formless, monochromatic world, most targets begin to panic. Soon after, the world begins to become colorful, with one wavy bands of one color after another. The number of colors depend on how skilled the user is with the genjutsu. Soon after, the target suffers slight blindness, head pain, and something similar to a seizure. The target tries to close their eyes, but their eyelid remain open, forced to watch the painful light show. The colors warp around rapidly and the target begins to lose their energy, dropping to the floor instantly. At the end, the world suddenly flashes white and the target returns to real world, suffering a massive headache. Depending on how intense this genjutsu was, the target can suffer slight disorientation to bordering a mental breakdown. This genjutsu opens the target to a variety of attacks.

This genjutsu is very intense and requires that the user doesn't move once, otherwise the technique will not reach full effectiveness. This genjutsu can also be dispeled by a skilled opponent. Lastly, the chakra cost needed drains the user once the genjutsu is over.

Trivia
This technique is named after opals, a gemstone that has a white, milky color when found raw and has shines of various colors once the stone has been polished and refined.