I want to develop a little tool to help visualize fireworks before using them in a show in Unity where the user can set several parameters and gets a preview of the firework effect in a preview window. To allow the user to customize color over time like I can currently statically do in the visual effects graph, I wanted to add a Gradient input field to my UI.
After fiddling around with manually trying to make things work, I stumbled upon the new UIElements / UI Toolkit and following this Medium post was able to render a simple text UI in a Panel Renderer. However the Gradient Field I added won't show up (which is quite reasonable because in the UI Builder it said something about "Editor only").
Just to make sure, the box on the left is what I mean:
I was strolling around in the Asset Store for a while but couldn't find anything like what I was looking for (just shaders and stuff to apply a gradient to UI elements amongst other things). Other searches led to tutorials on how to completely custom build a single color selection tool which both seemed like a larger effort and didn't allow creating a full gradient.
The question is: Is there some sort of library, package or tool I could use to add an input like that to my "game"? Or am I taking a completely wrong approach with this?