Taisuke Koyama went back to the rainbow gradient colour palette in 2013, I'm fan of his colourful photographic series and the experimental process he follows to get different textures on. His first rainbow based series is called Rainbow Forms, 2009 where he took photographs of posters taken in central Tokyo using a macro lens. The second one titled Melting Rainbow, 2010 Taisuke used the posters from the previous series and placed them in the balcony of his room to make them change the process of the surface (the ink was melt with the rain and snow and became dew drops with the heat from the sunlight.) then it was photographed. And for this last series Rainbow Waves he photographed them under water. See more;
