Video recorded under fluorescent lighting often has a green or yellow-green color cast. Skin looks pale and sickly. White surfaces appear slightly green. The overall image feels clinical and unflattering. This is one of the most common color problems in amateur and corporate video.
Why fluorescent lights cause a green cast
The color of light is described by two properties: color temperature (warm to cool on the yellow-blue axis) and tint (green to magenta axis, sometimes called the green-magenta shift).
Incandescent bulbs and sunlight produce light that falls cleanly on the yellow-blue axis. White balance (adjusting color temperature) corrects them perfectly.
Fluorescent lights use phosphors that emit light in spikes across the visible spectrum rather than a smooth continuous spectrum. These spikes often include excess energy in the green wavelengths, producing a green tint that exists independently of the color temperature.
Camera auto white balance adjusts for color temperature (warm/cool) but often does not fully correct the green-magenta tint. The result is footage that is the right warmth but has a green cast.
Modern LED lights can have similar issues. Cheap LEDs with low Color Rendering Index (CRI) produce spiky spectra that cause color casts. High-quality LEDs (CRI 95+) produce much more accurate color.
How to correct the green cast
The correction requires adjusting the tint/green-magenta axis, not the color temperature/warm-cool axis. Many video color tools provide both:
- Color temperature (or white balance): Adjusts the warm-cool axis. Moving toward warm adds yellow/orange. Moving toward cool adds blue.
- Tint: Adjusts the green-magenta axis. Moving toward magenta counteracts the green cast.
To fix fluorescent green: shift the tint toward magenta until skin tones look natural and white surfaces appear neutral white. The amount varies by light source, but typically +10-25% toward magenta corrects most fluorescent color casts.
How to judge correct skin tone
The most reliable reference for color correction is skin tone. Regardless of skin color (light or dark), healthy skin has a warm undertone. If skin looks green, yellow-green, or sickly gray, the tint needs correction toward magenta/warm.
Compare the corrected skin to your memory of what it looked like in person. If the person looked healthy and warm in the room, the corrected video should match that memory.
If you do not have a skin tone reference, look for whites in the frame: white shirts, white walls, white paper. Neutral white should not have a green or magenta tint after correction.
Mixed lighting situations
Many indoor environments have mixed lighting: fluorescent ceiling lights plus window daylight, or LED desk lamps plus overhead fluorescents. Each light source has a different color temperature and tint, so different areas of the frame have different color casts.
Correcting mixed lighting perfectly is not possible with global color adjustments (one setting for the entire frame). The correction that fixes the fluorescent-lit areas may over-correct the daylit areas.
For mixed lighting, find the compromise that makes the primary subject (usually a person) look correct. Accept that background areas under different lighting may not be perfectly neutral.
Prevention
Preventing fluorescent color casts at recording time is easier than fixing them in post:
- Set manual white balance: Hold a white or gray card under the fluorescent light and set custom white balance. This calibrates both temperature and tint simultaneously.
- Use high-CRI lights: Replace overhead fluorescents with LED panels rated CRI 95+ for video recording. These produce accurate color.
- Shoot near windows: Daylight overpowers fluorescent lighting. Positioning the subject near a window reduces the fluorescent contribution.
For footage already affected by green casts, the MediaBrew color adjustment tool lets you adjust the tint toward magenta and balance contrast directly in your browser.