The poppy is renowned both for its spectacular beauty as a flower, and for its vivid associations with remembrance for fallen soldiers, as well as its origin as a source for opium. Their colors can range widely through yellow, orange and red, and also purple and blue. In this particular case, we're going to look at the red-orange flowers from the garden of the Horse and Hound Inn in Franconia, NH.
Figure 1: Munsell colors for June 2013
The first thing to notice is that these flowers are spectacularly chromatic, right at the edge of what's possible to reach in paint. In direct sunlight, it's hard to look at anything else if one is in view. The main hue of these samples is 10R, which is exactly halfway between the “central red” of 5R and “central orange” of 5YR in the Munsell space. The petals below – which had fallen from the plants, and which the proprietors of the inn graciously permitted us to return to the studio for study and measurement – had already diminished in chroma by the time we were able to make the comparisons. We measured them at 10R 5/12, the maximum chroma in the Munsell glossy book for that hue and value, and we would estimate that the petals on the live flowers were at least chroma 14. That is a mixing challenge for any painter.
The other dominant hue on these flowers is the purple areas at the base, darkening to a nearly complete black in the center. This hue is 10RP, which is halfway between the “central purple” of 5P and “central red” of 5R. This is a terrific example of how colors that are actually very close in hue – here, only one-tenth of the distance around the color wheel – nonetheless can appear very different when there are substantial differences in value and chroma.
The inside of the flower, at its most chromatic point, is approximately 10RP 2/4 to 2.5/4 (our matte chip here is value 2.5):
The underside of the petal shows a range of 10RP 3/4 to 10RP 4/4. All very close to the orange of the petal on the hue axis, but quite far on chroma, and a good distance in value, cause to the dramatic difference in color appearance.
This case is also interesting because the chroma of all three measurements is constant at 4, yet as it lightens, it appears to fade in intensity somewhat and get gently dimmer, or take on a somewhat more pastel attribute. (Remember that pastel, in color terms, is simply a high-value color with a relatively low chroma.) The reason for this is that the maximum possible chroma for each value increases at these value levels; 10RP's maximum chroma (in the Munsell Matte book) at value 2.5 is 4; at value 3, its maximum chroma is 6, and at value 4, its maximum chroma jumps to 12. This means that although the chroma – the perceptual distance from a neutral of the same value – is constant throughout this progression, the saturation – the ratio of chroma to value – is diminishing, which gives the illusion that the colors are dimmer, although they aren't.. The terms chroma and saturation are often confused in color mixing, but they shouldn't be, and this is why.
The center of the flower is so dark that it is just about impossible to get a reading on it with any hue indication – it barely reflects enough light to measure, at least without the benefit of extremely sophisticated equipment. Although it is likely a very, very low-value 10RP – below value 1, possibly near 0.5, which is about as dark as pigment can reach – for all intents and purposes it can be considered black. Since most commercially available black paints are actually purple-blue in hue, it would be very close to simply use it directly from the tube, allowing it to blend with the 10RP 2.5/4, to achieve the color in the center of the petals, and the flower itself. (This is one good example of a time to disregard the oft-repeated admonition not to use black! By all means, use it when you need it. Just understand what it is!)
(We would like to thank the hosts of the Horse and Hound for their gracious hospitality, and their indulgence of our color science enthusiasm for their garden.)