Never saw one of those in the wild. But I have seen NaviLens codes (on cereal packaging), they use color as well: https://www.navilens.com/en/ https://www.navil

Never saw one of those in the wild. But I have seen NaviLens codes (on cereal packaging), they use color as well: https://www.navilens.com/en/ https://www.navilens.com/en/