Before revision: The Forel Ule scale, a color comparator scale, has been recently described by Wernand and van der Woerd (M. R. Wernand, H. J. van der Woerd, "Spectral analysis of the Forel-Ule Ocean colour comparator scale.
After revision: The Forel Ule scale, a color comparator scale, has been described by Wernand and van der Woerd (M. R. Wernand, H. J. van der Woerd, "Spectral analysis of the Forel-Ule Ocean colour comparator scale.