If you are looking for swatch library and color pallet options for After Effects, then Tim Constantinov has you covered with Swatcher, which will allow you to load custom color pallets from popular files or even a link.

Swatcher is a script for Adobe After Effects, loading color palettes from several color services

Swatcher will not only load color pallet files, but it also automatically suck-up color from images, and provides a simple way to recolor your After Effects composition based on those colors with the Colorizer function which will find each color in your selected layers such as Solid Layers, Text and Shape Layers (choosing for colorize each fills and strokes inside content parameter).

Tim notes that as of this posting the link for the script is available only for registered videohive users in the “beta” Add-ons category on videohive
however the regular link should be available soon.

For now, if you are registered with videohive, check out the Swatcher After Effects Color Pallet script here. The Swatcher script for Adobe After Effects loading color palettes from several color services will be available here.