Upload custom legend for AGOL layers
PROBLEM: There are times when the stock legends in ArcGIS Online (AGOL) are not exactly what I want to show my users.
IDEA: I would like the ability to upload a custom PNG, JPG, or similar file to use for a layer's legend. I know my data and how I want users to view it.
I don't want to get too far down in the weeds on how this is done, but ideally, this could be specified with the layer's visualization. That would make it the default when the layer is used in a map and derivative products (dashboard, story map, experience, web map builder, field maps, etc.), but also could be overridden in the map, including uploading a custom legend image.
EXAMPLES: Here is a legend for a stretched raster published from Pro as a tile layer in AGOL (screenshot below). The user has no idea what values the intermediate colors are. For example, if you see a yellow color on the map, how precisely could you determine it's value using this legend? It would be a wild guess. Also, the range goes from high to low, which is the opposite of what I'd expect.
In another example, I might want to create a legend like this for a stretched raster layer:
Or perhaps something like this:
NOTE: This idea is NOT a request to improve the legend display to natively accommodate various use cases, aside from the stated request to upload our own image. AGOL's legend capability could be improved six ways to Sunday and I'd bet there will still be one more use case that isn't covered. Enabling us to upload images for our legend would give us the most flexibility.