Fix your gaze on this until the after-images cause the colours to shift.
After-images (with eyes open or closed) have always interested me. They played a significant part in my early attempts at meditation: gazing at a daylit window, closing my eyes, focussing on the after-image while it faded through a spectrum into dark violet.
This evocation of after-images is one of two early works (1997-9) with simple animated GIF images.