I write about how you can do this in a few places. Basically, you can follow the pattern in this sample: https://developers.arcgis.com/javascript/latest/sample-code/visualization-update-data/
This is also described in this "Time styles" guide: https://developers.arcgis.com/javascript/latest/visualization/data-driven-styles/time/#attribute-ani...
Here are some blog posts that provide context and more examples:
https://www.esri.com/arcgis-blog/products/js-api-arcgis/mapping/mapping-large-datasets-on-the-web/
If you get it working, I'd love to see how it turns out.
Dear Jay,
As I undertstand you have about 3000 unique feature layers, and all of them are polyline feature layers. They have a field in their attribute table which has about 50 different values. you want to apply a method to show your polylines with different colors. is it right?
Could you please explain in details better your situation.
I have attached a sample project which I have done with dictionary rendere for 16 different unique values for a polyline feature layer. if you explain better the situation I can help better.
good luck