In ArcGIS Online, feature symbology can be driven by Arcade expressions reading feature attributes, but not labels.
IDEA: Add option to use arcade to dynamically set labelling properties (like text colour) based on attributes against a feature (e.g. a colour hex code).
USE CASE: I'm setting up a Personal Markup layer where the annotations created by the user persist between sessions (Text/Markers/Lines/Areas) and aren't lost as soon as the map viewer is closed or refreshed. Currently, I can create a domain in a point layer (where the point symbol itself is invisible and only the label is visible) with a list of predetermined colours stored as hex values (e.g. Black = 000000) but I can't dyanmically pull that value into the label formatting. Instead I have to setup different label classes using filters for each colour.
