Scientists who study the natural world do more than tally numbers. Sometimes making an accurate scientific observation comes down to finding the perfect word to describe the shade of dried lavender flowers or the breast of a screech owl. In the 19th century, naturalists had Werner's Nomenclature of Colours to refer to—and now anyone looking to expand their color vocabulary can access the book's contents online, Fast Company reports.

Published in 1814, painter Patrick Syme designed the guide based on the work of geologist Abraham Gottlob Werner. It features 110 distinct hues, each with a name, number, and a list of the animals, plants, and/or minerals that feature it in nature. Prussian blue, for example, naturally occurs in blue copper ore, the stamina of bluish purple anemone, and the spot on a mallard drake's wing, while wine yellow can be found in the saxon topaz, white currants, and the body of a silk moth. The book was used as a handy reference guide by researchers recording observations the field, including Charles Darwin.

Now, using free scans of the book from the Internet Archive, designer Nicholas Rougeux has transformed it into an interactive digital experience. The original color swatches and descriptions are included, as well as some modern additions. Click on a color and the entry will expand to show photographs of the plants, animals, and minerals mentioned. Rougeux has also made posters based on the manual available on the website.

Werner's Nomenclature of Colours may have been the color bible of its time, but it still covers just a fraction of all the shades that have been named. After exploring the digital guide online, continue to grow your knowledge with this color thesaurus.

[h/t Fast Company]