Green vs blue-grey eyes

Green eyes read as having a definite colour of their own, usually consistent across the iris and often with a warm gold cast near the pupil. Blue-grey eyes read as cool and comparatively colourless — the impression is of a pale, unsaturated iris rather than of a green one. The difficulty arises with the least saturated green eyes, which in poor light can look simply pale and cool.

Typical distribution: Green is usually distributed fairly evenly with any warm flecking concentrated centrally; blue-grey typically shows a gradual shift between its bluer and greyer readings across the iris rather than a distinct pattern.
Undertone: Green carries a warm-to-neutral undertone from the moderate melanin present; blue-grey is consistently cool, with little melanin in the front layer of the iris to warm it.
Central or outer ring: A warm gold or amber inner ring is common in green eyes and points away from blue-grey. A darker limbal ring at the outer edge occurs in both and does not distinguish them.
Lighting effects: Both shift noticeably, but in different directions. Green eyes tend to look warmer and browner under warm indoor light; blue-grey tends to look bluer in bright daylight and greyer under overcast or indoor light. Surrounding colour matters more for blue-grey than for green, because there is less of its own colour to dominate.

Why classification is subjective

The boundary is a question of how much saturation counts as a colour. Blue-grey is not a category most classification systems record at all, and a low-saturation green sits close enough to it that observers reasonably disagree.

This pair is particularly vulnerable to automatic white balance. A cool-biased image can strip the warmth from green eyes until they read blue-grey, and a warm-biased image can add enough warmth to blue-grey eyes to suggest green that is not there.

No photograph or online colour-picker tool can definitively classify which of these categories a specific pair of eyes belongs to — classification is inherently somewhat subjective, and lighting/camera effects change the apparent result.

Related profiles

Green eyes Blue-grey eyes

Green vs blue-grey eyes

Typical distribution

Green is usually distributed fairly evenly with any warm flecking concentrated centrally; blue-grey typically shows a gradual shift between its bluer and greyer readings across the iris rather than a distinct pattern.

Undertone

Green carries a warm-to-neutral undertone from the moderate melanin present; blue-grey is consistently cool, with little melanin in the front layer of the iris to warm it.

Central or outer ring

A warm gold or amber inner ring is common in green eyes and points away from blue-grey. A darker limbal ring at the outer edge occurs in both and does not distinguish them.

Lighting effects

Both shift noticeably, but in different directions. Green eyes tend to look warmer and browner under warm indoor light; blue-grey tends to look bluer in bright daylight and greyer under overcast or indoor light. Surrounding colour matters more for blue-grey than for green, because there is less of its own colour to dominate.