Found something HUUUGE!
I was browsing the GitHub wiki page and found something in the code snippets!
https://github.com/nesbox/TIC-80/wiki/code-examples-and-snippets#pal-function
It's a little function that does exactly what I was talking about! It takes the color index, and the RGB values for the desired color, and modifies the palette. I imported it into one of my scripts and had it running in seconds!! Just leaving this link for anyone interested.