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Self-screening · ~2 min

Color vision check.

A Farnsworth D-15 style hue-arrangement test. Starting from a fixed reference chip, arrange the loose color chips so they flow into the smoothest possible gradient — then see how your ordering compares to a perfectly even hue circle.

Jump to the chips

Arrange the color chips

Every chip sits at the same brightness and intensity — only the hue changes. That's what makes small color-discrimination differences show up: the arrangement gets harder wherever two neighboring hues start to look alike.

Reference
(fixed)

    Drag a chip with your mouse or finger, or focus a chip and press the arrow keys (or the ◀ ▶ buttons) to move it left or right.

    Clinical background

    The science behind this

    Normal color vision is trichromatic — it relies on three cone types tuned to long (L), medium (M), and short (S) wavelengths. Most color-vision deficiency comes from an anomaly or absence in one cone type, which makes certain hues genuinely indistinguishable.

    Arrangement tests like the Farnsworth D-15 exploit this: people confuse hues that fall along predictable "confusion lines," so they place the caps out of order. Plotting their sequence around the hue circle produces crossings whose direction reveals the type of deficiency.

    What the pattern suggests

    • Protan / deutan — red-green confusion from L/M cone anomalies; the most common form, X-linked, affecting roughly 8% of men
    • Tritan — blue-yellow confusion along the S-cone pathway

    Limitations

    • Uncalibrated screens, display gamut, and room lighting all shift the colors you see.
    • It screens and roughly classifies — Ishihara plates and anomaloscopy remain the standards.