In ArcMap I add a single layer (wilderness areas in the U.S.) and symbolize all polygons with the same symbol from the ESRI Optimized style (100-year Flood Overlay). This symbol is a diagonal hatching. The only change I make is to the outline and hatching color, and I choose one of the colors from the ESRI Optimized style. I then publish the map document to our organization's ArcGIS Online (AGOL) site as a feature service, allowing only the 'Query' operation under 'Feature Access'.
When I open the 'Details' page for the resulting service and click the link found under 'Layers', the 'Drawing Info:' section specifies (see below) that a simple diagonal fill and a simple line outline are to be used in rendering the polygons and that the color of both the outline and diagonal fill is the same (a green).
1. What's happening? 2. Can I do anything to get the symbology I intend? 3. Is it just that AGOL supports only solid fills at this time? If so, what are the plans for more robust symbology support?
Please vote upon the following idea which is precisely about this in order to promote the following solution.
While one can use the solution directly in custom javascript pages, we'll have to wait for ESRI to push it on the official API for it to become available on ArcGIS Online by default.