UNSATURATED WARM COLOR ZONES IN THE COLOR WHEEL
The unsaturated color zones only appear within the magenta/yellow third of the color wheel, not in the yellow/cyan or cyan/magenta sides. This effectively splits the color wheel into two parts, with the unsaturated color areas roughly centered around the "warm" end of the warm/cool color contrast. In most hues, a loss of chroma causes a color to shift toward gray while retaining the recognizable hue character of the color. A dull green is still green, and a dull violet still violet. Among warm hues, the shift is not toward gray but toward a subjectively different color. This is clearly marked by the fact that people do not use the spectral hue labels (yellow, orange, red) to refer to the unsaturated form of the same colors (which are instead called gray, ochre, tan, brown or maroon). As we decrease color chroma from its most intense value, the color at first appears to darken and mellow slightly, but at around a saturation of 80% to 50% (depending on the hue), these changes take on a different character entirely. This transition occurs at different points, depending on the relative luminosity of the hue: high for highly reflective yellows, low for dark reds.
This table summarizes the most common transitions:
UNSATURATED WARM COLOR ZONES
CIELAB hue angle - color name at maximum saturation:
Percentage of chroma (%) = new color names.
90 - Light Lemon Yellow:
80% = green gold; 60% = olive green; 40% = gray green.
70 - Deep Yellow:
70% = gold ochre; 50% = raw umber.
50 - Orange:
60% = burnt orange; 50% = burnt sienna; 30% = burnt umber.
30 - Red:
50% = maroon; 35% = burnt umber.
10 - Carmine:
45% = maroon; 35% = violet umber.