About the FM100 Hue Test

The Farnsworth-Munsell 100 Hue Test was developed by Dean Farnsworth in 1943 and is still widely used by eye-care professionals, colour scientists, and industries where accurate colour judgement matters (printing, textiles, paint, display manufacturing). It arranges 85 coloured chips in four trays that must be sorted in spectral order.

FM100 scoring methodology

The total error score is calculated as the sum of squared deviations between each chip's placed position and the expected spectral sequence. For each cap, the score contribution is (Δleft − 1)² + (Δright − 1)² where Δ is the absolute difference in cap numbers between neighbours. Population studies show:

Score 0–4: superior colour discrimination
Score 5–16: average colour discrimination
Score 17–100: below-average colour discrimination (age-related decline is normal)
Score 100+: possible colour vision deficiency; clinical assessment recommended

Scores naturally increase with age even in individuals with normal colour vision.

Types of colour vision deficiency

Deuteranomaly (reduced green sensitivity): the most common form, affecting approximately 5% of males and 0.4% of females. Errors clustered in the green–red region.
Protanomaly (reduced red sensitivity): affects ~1% of males. Also produces red–green errors but with additional confusion in the red–purple range.
Tritanomaly (reduced blue sensitivity): rare (<0.01% of population). Blue–yellow confusion; errors appear in the blue–green region of the hue circle.
Achromatopsia: complete colour blindness. Extremely rare; only rod photoreceptors function, producing monochromatic vision with extreme light sensitivity.

Testing environment recommendations

Results are significantly affected by testing conditions:

Use a calibrated monitor at a standard brightness level (100–120 cd/m²)
Test in neutral ambient lighting - avoid warm incandescent light, which shifts perceived hues
Avoid glare or reflections on the screen
Test without tinted glasses or contact lenses that alter colour perception
Take the test when rested - fatigue degrades colour discrimination performance

This browser test uses 20 chips and screen-rendered HSL colours, so results are only approximate. For a clinical assessment use calibrated physical test materials.