Hi swim-package,

This is exactly how it is set up. See image.

Screen Shot 2023-04-11 at 2.54.48 PM.jpg

It is based on the Vertex Map Tag. This Tag, while named wisely, is inside of the Vertex Attribute.
The Freeze layer stores the data.

If you need additional colors from Splines that hit later, use another Vertex map Tag, drive the next mask with it, and adjust the color of that layer.

Cheers