Custom gradients in grasshopper

How can I automate the addition / removal of multiple gradients by giving lists of color values and stop positions. Don’t want to do this manually, and would like to add them quickly.

I know that this can be done on the fly, i.e., using “pufferfish” “tween colors”, but I would like to store them for later use.

I have looked through appdata and programfiles to no avail.