Perceptual organisation is an important factor in colour vision.
We studied a new version of White's illusion, where target gray patches could be intentionally grouped with other gray patches aligned with either the black or white stripes of the White's pattern. We found that the targets appeared lighter when they were intentionally organised in phase with the black stripes of the White's pattern and darker when they were intentionally organised in phase with the white stripes. This finding supports the idea that intentional perceptual organisation influences colour appearance.