Animation/Design Question That Incorporates Horizontal Scroll


I am currently working on a project and had a question regarding a horizontal scroll I have implemented. I currently have the track and everything in place. I am struggling with how to figure out the best way to create it to match part of my Figma design (if possible). Please see the image below to reference the section I am trying to create from Figma.

My question is what the best way to get the spectrum UV Wavelength in the Horziontal Scroll so it can have a gradient across the horizontal scroll while aligning with each of the sections you see. Please see my read only link to see what I have completed so far.

Any help is greatly appreciated.

Thank you,

Read Only Link: Webflow - AADI

Published Link:

Here is my public share link: LINK
(how to access public share link)