Fig 1. Schematics of the experiment.

Subjects manipulated the hue of a central test patch using a gamepad (left). The test patch was embedded inside a coloured Mondrian (Condition 1) or a mid-lightness grey background (Condition 2). Two colour names were presented at the bottom of the screen and subjects had to produce colours equally distant from those represented by the names. They were only allowed to modify the colour along predetermined paths (e.g. lines or concentric arches of randomised radius in CIE L*a*b* space), which started and ended well inside the consensus colour-name regions corresponding to the colour names on the screen. There were no time or head movement constraints.