Colors, especially color saturation is very closely linked to value. I have honestly no idea why this is, but what I do know is that every artist needs to think about the color of something in the black and white process if the saturation of a specific color is going to be important later in the design. The most common example of this is going to be the color red. If a design was initially worked out in B/W without much thought to the color, when it comes time, the saturation of said design might go sideways. Red is a very dark valued color by nature, so if it needs to be saturated, we're talking about establishing it's value range with a minimum of a 7 in value. Other interesting properties, concerning traditional paint mixing primaries (Red/ Yellow/ Blue) are ideas like yellow having the narrowest saturation range, .5-2 out of 10 on a B/W scale, and Blue holding the largest value range in it's saturation properties, 5-9ish on the same B/W scale. Red hovers in around 6-8. I've found when mixed with other primaries, these scales just slide linearly. So orange, as an example will have properties of yellow and red, with a saturation range of 4-6 as an example. Paying attention to these properties is the difference between light sources like candles becoming "milky" and conversely providing the warm full range of light you'd expect to feel in a natural way.