What do you call the process of marking changes in color or luminance over time in After Effects?

The correct term for the process of marking changes in color or luminance over time in After Effects is animation. Animation in this context refers to the process of creating dynamic changes in visual properties over the timeline, which includes adjustments to color and luminance among other visual attributes.

In After Effects, you can animate properties like color effects, brightness, contrast, and many other parameters using keyframes, allowing for smooth transitions and alterations throughout the duration of your composition. By setting keyframes at different points in time, you can define how these properties change, creating a visual progression that can enhance storytelling or artistic expression in your projects.

Color correction typically refers to the adjustment of colors in footage to achieve a desired aesthetic or to correct for lighting issues. Motion tracking involves following the movement of an object within a scene to apply effects or layers dynamically. Compositing is concerned with combining visual elements from different sources into a single image or sequence. While all these processes are essential in After Effects, they do not specifically address the continuous changes in color or luminance over time as described in the question.