Wolfram Technology Guide: Automated Computational Aesthetics  previous | next 
Automatic Visually Distinct Plot Markers
Mathematica automatically picks visually distinct plot markers to distinguish different datasets.
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Click for copyable input
ListPlot[Table[BesselJ[n, x], {n, 4}, {x, 0, 15, .2}], 

 PlotMarkers -> Automatic, Joined -> True]
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