Chroma Key

Chroma key, commonly called green screen or blue screen, is a visual effects technique that removes a specific color from footage and replaces it with another image or video. The subject is filmed against a uniformly lit colored background, typically bright green or blue because these colors are least present in human skin tones. Software then makes that color transparent, allowing compositing of the subject over any background such as fantasy landscapes, news sets, or virtual environments.

For a YouTube video with custom backgrounds, you set up a green screen behind your desk, ensuring even lighting without shadows or wrinkles in the fabric. Bright softboxes illuminate the green screen separately from your key light on the subject to avoid green spill. In post-production using Premiere Pro or OBS, you apply the Ultra Key effect, adjust the tolerance to cleanly remove the green without affecting hair edges, then place your desired background on a layer below. Fine-tuning edge softness and spill suppression creates a convincing composite.