In Illustrator, I want to use a color that is a placeholder so that later I can change it in one place, and everything using that color will be changed. Simply knowing what AI calls this feature might be enough to find it in the online help! I’m pretty sure I saw this some time ago.
More generally, can I create a group of theme colors, and change them as a set? What about colors based on theme colors as a starting point, but (e.g.) made lighter or otherwise transformed?