Short answer
Leaves absorb blue and red strongly for photosynthesis and let green and far-red through or reflect them, so light in canopy shade is dimmer and relatively richer in green and far-red than open daylight. Sunflecks breaking through gaps restore near-daylight in moving patches, so a woodland floor is a mosaic of two very different spectra.
Chlorophyll absorbs strongly in the blue and the red and weakly in the green, and leaves transmit and reflect much of the far-red just beyond the visible. Light filtering down through several layers of leaves therefore loses blue and red faster than green and far-red. Plant scientists track this with two ratios: red to far-red, which is about 1.1–1.2 in open midday sunlight and falls steeply in shade, and blue to green, which is also lower in shade than in sunlight. Plants read these ratios as a signal of competition; for human vision, the visible consequence is a dimmer, greener light.
Canopies are not uniform. Where gaps line up with the sun, sunflecks reach the ground: bright patches of nearly direct sunlight, enriched in blue and red compared with the surrounding shade because the leaves have not filtered them. Sunflecks move with the wind and the sun, lasting seconds to minutes. An object on a woodland floor can therefore be lit by two very different spectra at once — green-shifted shade on one side, sun-coloured light on the other — and its apparent colour changes from moment to moment as the flecks move across it.
Chromatic adaptation discounts much of the green cast, so a wood rarely looks strikingly green-lit to someone walking in it. The shift shows most on things we know well: skin looks paler and slightly sallow, a white shirt looks faintly green, and red flowers or berries look darker than in the open because there is little red light for them to reflect. Photographs taken under canopy, which do not adapt the same way, often show a pronounced green or yellow-green cast on people.
Garden and landscape designers working under trees are choosing colours for a green, dim and dappled light. Reds lose most; pale colours, whites and yellow-greens hold up; blues are subdued by the low blue content. For photographing people in woodland, a reflector or fill light restores the missing red and blue on faces, and setting white balance from a grey card in the shade — not in a sunfleck — removes most of the cast. For judging any colour sample, move into a clearing first.
Why: Light filtered through leaves is depleted in red and blue; the camera does not adapt as the eye does.
Fix: Set a custom white balance from a grey card in the shade and add a warm reflector or fill light.
Why: Little red light reaches the ground in canopy shade.
Fix: Choose whites, creams, pale yellows and variegated foliage for shaded beds.
Each statement is labelled by kind — established fact, a standard’s requirement, observed market data, a convention, or Colourwise’s own interpretation or analysis — with the strength of the evidence behind it.
FactStrong evidence
As radiation passes through canopy layers, absorption by leaf pigments lowers the red/far-red ratio from values of about 1.1–1.2 in midday sunlight.
Source: Making the most of canopy light: shade avoidance under a fluctuating spectrum and irradiance
FactStrong evidence
Canopy shade has a lower blue/green ratio than sunlight, while sunflecks are enriched in blue and red relative to the surrounding shade.
Source: Making the most of canopy light: shade avoidance under a fluctuating spectrum and irradiance
Colourwise interpretationModerate evidence
Under canopy shade, red surfaces lose the most apparent colour and pale or yellow-green surfaces the least, because red light is most depleted.
Based on: Follows from the spectral changes in canopy light reported in the cited review; not measured on specific surfaces.
Reviewed 29 September 2026. Colourwise summarises its sources in its own words and does not reproduce standards text or proprietary colour data. Spotted an error? Tell us.