Last month I posted that darker luminosities increase color saturation. I now find out that I was wrong.  It actually depends (heavily) on the color.

A better description: reds and oranges do increase in saturation. They also alter hue – oranges approach red, red gets deeper.  Blues stay consistently blue (but darker and lighter).  Yellows increase saturation at brighter luminosities – this was a shock to me (and yet, it makes sense).  Purple ranges from a deep violet to a lilac color.

So shooting for saturation: yes, slightly darkening does increase saturation – especially for blues and reds.  For others, there may be unintended (or intended) consequences!

Insight and information from Perfect Exposure.  Highly recommended reading if you’re new-to-intermediate and looking for in-depth info.