Institute for Colour Perception · Basel · est. 1987
CHRMA
The institute studies the gap between light and the seeing of it. Four permanent instruments hang on this wall — and the wall itself is the fifth: its accent hue completes one slow orbit of the OKLCH colour circle every ninety seconds. Nothing on this floor is a picture of colour. Everything is colour, computed live.
Current protocol: live wall, constant chroma, no printed pigments
Please touch the exhibits — every instrument on this floor is live
Gradient Field Synthesiser
Five points of pigment suspended in a field. Drag any point and the field re-solves — interpolation runs in OKLab, the laboratory's preferred space, so mixtures stay luminous instead of collapsing into grey.
Canvas, pointer events, inverse-square interpolation in OKLab
Acc. 2024.011 · Interactive — please touch
OKLCH Ramp Comparator
The classic argument, staged. Two ramps descend from near-white to near-black in eight equal strides. The left obeys OKLCH; the right trusts HSL's so-called lightness. The instrument measures every swatch as your eye receives it — CIE L* — and prints the stride lengths underneath. One staircase is even. One is not.
OKLCH — perceptual
HSL — naive
OKLCH v. HSL, nine strides, measured in CIE L*, gamut-mapped per step
Acc. 2023.047 · Interactive — please touch
Simultaneous-Contrast Apparatus
After Albers. The two inner swatches are one and the same colour — the wall around each is lying to you. Drive the slider to push the swatches toward the seam until they touch and become a single uninterrupted bar. Your eye will concede; it always does.
After Josef Albers, restaged in oklch(); grounds drift with the wall
Acc. 1963.002.R · Interactive — please touch
Spectral Ribbon
A continuous interpolation across the entire hue circle at constant lightness and chroma, gamut-mapped column by column. Tap the ribbon to pin a stop; tap a pin to release it. The ribbon hands you its stops as working CSS.
Full-gamut sweep · L 0.72 · C 0.135 · gamut-mapped per column
Acc. 2025.003 · Interactive — please touch
Field Notes
Selected studies from the institute's register, 2019–2026. Offprints may be requested at the front desk.
- CR-088Afterimage decay under sodium-vapour illuminationPublished
- CR-097Hue-naming boundaries across fourteen languagesPublished
- CR-104Simultaneous-contrast thresholds in peripheral visionPublished
- CR-113Chromatic adaptation in seventeen minutes of duskIn review
- CR-121Perceptual uniformity of wide-gamut display primariesPublished
- CR-129Memory colour of household objects, 1978–2023In review
- CR-137The gallery wall as instrument: ambient hue driftOngoing
The Institute
CHROMA occupies the third floor of a former pigment mill at Gerberngasse 14, Basel. It was founded in 1987 by the perception psychologist Ilse Vandermeer, who argued that colour science belonged on gallery walls, not in drawers. The collection now holds 214 instruments, of which four are on permanent display.
Visiting
Tue–Sun, 10:00–18:00
Admission free.
The wall hue cannot be requested.
Credits
Direction — Dr. I. Vandermeer
Instruments — T. Okabe, R. Fiel
Conservation — M. Duarte