The orange and Yellow patches visually matched some samples of oranges and lemons, both freshly picked, not dyed.
Some blue flowers, most notably the morning glory of the variety "Heavenly Blue," are prized for their blue color, but frustrate the attempts of photographers to depict them.
…speaking as a longtime cultivator of morning glories—I’m gazing at a “Heavenly Blue” variety in bloom as I write [0]—they are absolutely correct; and I love that this fact informs the norms of the entire photographic industry!
And, of course, the bottom line:
Having developed a well-characterized test object, we feel obligated to point out that color-reproduction systems hardly ever reproduce all colors exactly. The practical limitations of such processes make perfect color reproduction virtually impossible.
Comments
The paper where the target values originated:
https://home.cis.rit.edu/~cnspci/references/mccamy1976.pdf [1976, PDF]
It’s a charming read, with lines like
…speaking as a longtime cultivator of morning glories—I’m gazing at a “Heavenly Blue” variety in bloom as I write [0]—they are absolutely correct; and I love that this fact informs the norms of the entire photographic industry!
And, of course, the bottom line:
[0] https://www.gardenia.net/plant/ipomoea-tricolor-heavenly-blu... — and if those charm you, may i recommend the ‘Keiryu’ / ‘Mountain Stream’ variety, which, needless to say, is far more impressive than the photos suggest: https://organicplantit.com/product/keiryu-mountain-stream-mo...