Within the Spotfire Analyst client, you have a color set on a layer within a Map which is displayed within the legend.
Once it is saved and viewed within the Web Player, the color legend is not displayed.
Rootcause: Open the settings for the map layer and select Color. You may have the color set, but
no column is defined.
In the following screenshot, you can see 'None' as value selected for 'Columns'. This causes the Legend not to be visible in Web Player.