Perhaps different people experience this image differently. For me, viewing the image on an iPhone, with no squinting at all, the balls look strikingly red, gre

Perhaps different people experience this image differently. For me, viewing the image on an iPhone, with no squinting at all, the balls look strikingly red, green and blue. It's only after zooming in on the image, that I convinced myself that the balls were brown with colored bars over them. As others have suggested, perhaps a small image size is what makes this illusion work.