Colours can be ordered, like numbers on a line. Isaac Newton did this in his book Opticks, in 1704. Cloth lets children do it with their hands and their eyes.
The colour wheel
Wikipedia says “the color wheel dates back to Isaac Newton’s work on color and light.” In his book Opticks, Newton “presented a color circle to illustrate the relations between these colors” (Wikipedia: Color wheel). A rainbow runs red, orange, yellow, green, blue and violet. The wheel joins the ends into a circle.
Warm and cool
Warm colours “are often said to be hues from red through yellow, browns and tans included”. Cool colours “are often said to be the hues from blue-green through blue-violet, most grays included” (Wikipedia: Color theory). The same page says the idea “seems related to the observed contrast in landscape light”, and notes “a historical disagreement” about which colours anchor the two ends. So warm and cool are conventions, not laws.
Spectrum
Spectrum is one of the studio’s eleven patterns. Its own words are “Cool on the left, running warm to the right.”
In the code, each column of the panel has a target hue. The left column aims at a blue-green. The right column aims at a red. The columns between run in steps round the wheel. The studio picks the cloth whose hue is nearest each column.
Cloth with very little colour, such as grey, has no clear hue. The studio counts it as a poor fit anywhere along the wash.
- Open the studio and the Sample box.
- Press Spectrum.
- Read the panel from left to right. Which cloths sit in the cool columns? Which in the warm?
- Ask which cloth was hardest to place, and why.
Why daylight matters
The studio measures a cloth’s colour from the middle of its photo. It cannot tell if the photo has the wrong colour in it. Its own advice is “For best results, photograph it in daylight.”
Light changes how a camera sees colour. A photo with a colour cast looks as if “everything in the image appears to have been shifted towards one color” (Wikipedia: Color balance). Cameras try to correct this by working out the colour of the light, so that white looks white. They do not always get it right. Indoor bulbs give a yellower light than daylight. Wikipedia puts daylight at 5,500 to 6,500 kelvin, and describes the 2,700 to 3,000 kelvin of warm indoor bulbs as yellowish (Wikipedia: Color temperature). A photo taken under that light and not corrected can show the cloth with a yellow cast.
So we photograph by a window, with no flash and no coloured light. A true colour puts the cloth in the right column.