Sadly the undocumented mechanism behind Simon's splitstyle no longer works in Mathematica 10.0 or 10.1. Post-processing(1),(2) remains an option as does use of ListPlot. While pure post-processing is possible, in a bid to make this answer unique I shall instead define styleSplitter as a function that extracts the PlotStyle option from an unevaluated Plot expression. If none is present the default for that plot type is taken from Options.
SetAttributes[styleSplitter, HoldFirst] styleSplitter[plot : h_[___, op : OptionsPattern[]]] := MapAt[ ListLinePlot[Cases[Normal @ #, Line[x__] :> x, -3], PlotRange -> Full, PlotStyle -> OptionValue[h, {op}, PlotStyle] ][[1]] & , plot , 1 ] Test:
g[y_] := Total[Table[1, {z, 1, Round[y + 1]}]]; Plot[ Table[g[x*n], {n, 1, 3}], {x, 0, 1}, PlotStyle -> {Blue, Orange} ] // styleSplitter 
Because styling is done by ListLinePlot itself automatic behaviors such as style cycling are preserved.