Hello, Yellow

Sunshine in feathered form

Female Olive-backed Sunbird, North Queensland. © Bronwen Scott.

I planned to photograph a pair of Olive-backed Sunbirds (Cinnyris jugularis) as a reference for a drawing. The male was far too flighty, so I concentrated on the female while she perched on an emerging palm frond. This saved me from having to reproduce the iridescence of the male’s fancy bib — shades of purple and blue created entirely by tricks of the light. But I hadn’t thought about the yellow. How would I capture that brilliant yellow?

The colour comes from carotenoids in the feathers. Carotenoids are nearly ubiquitous in living organisms — they make pumpkins orange and egg yolks yellow, they are found in young leaves and dying leaves, and they protect cells from oxidative stress. But they do not create just one shade of yellow. The pigments range from a pale lemon wash to deep orange and beyond.

In 1774, geologist Abraham Gottlob Werner put together a list of mineral colours as part of his work Von den äußerlichen Kennzeichen der Foßilien. Over following years, the list of colours was translated, reworked and expanded into Werner’s Nomenclature of Colours, with Additions, arranged so as to render it highly useful to the Arts and Sciences. The definitive version of Werner’s reference was that of botanical artist Patrick Syme, who added hand-painted samples of colour. Each was was accompanied by an example of its…