Splices cuttlefish chromatophore genes into human dermal cells, allowing voluntary color-shifting across the visible spectrum. The baseline installation covers the face and hands; full-body coverage costs three times as much. Street-level clinics offer a budget version that only shifts between two or three preset colors. High-end Helix Biosystems packages include emotional reactivity — the skin changes hue in response to mood unless the user consciously overrides it. In the Shelf, mood-reactive skin is considered honest. In corporate towers, it's a liability. Most users learn to suppress the emotional bleed within a few weeks, but stress, alcohol, and strong emotion can break through the override. Children born to two chromatophore-positive parents sometimes express the trait naturally, without installation.