plotting - Match colors to plot themes

How do I get the colors to match the plot theme when I use a PlotLegend that is separate to the plots? I have had a look at How to access new colour schemes in version 10? but can't seem to find what I need. Here is some data and an array of plots.

Initialization

data1 = 
 {Table[{x, Sin[x]}, {x, 0, 2 π, 0.1}], 
  Table[{x, Sin[2 x]}, {x, 0, 2 π, 0.1}], 
  Table[{x, Sin[3 x]}, {x, 0, 2 π, 0.1}]};

data2 = 

 {Table[{x, BesselJ[1, x]}, {x, 0, 2 π, 0.1}], 
  Table[{x, BesselJ[2, 2 x]}, {x, 0, 2 π, 0.1}], 
  Table[{x, BesselJ[3, 3 x]}, {x, 0, 2 π, 0.1}]};

data3 = 
 {Table[{x, BesselJ[4, x]}, {x, 0, 2 π, 0.1}], 
  Table[{x, BesselJ[5, 2 x]}, {x, 0, 2 π, 0.1}], 
  Table[{x, BesselJ[6, 3 x]}, {x, 0, 2 π, 0.1}]};

data4 = 

 {Table[{x, BesselJ[7, x]}, {x, 0, 2 π, 0.1}], 
  Table[{x, BesselJ[8, 2 x]}, {x, 0, 2 π, 0.1}], 
  Table[{x, BesselJ[9, 3 x]}, {x, 0, 2 π, 0.1}]};

opts = 
 {Frame -> True, Axes -> False, 
  FrameLabel -> {"Time/s", "Pressure/Pa"}, ImageSize -> 280, 
  BaseStyle -> {FontFamily -> "Times", FontSize -> 12}, 
  PlotTheme -> "Scientific"};

Result

Column[
  {Row[
    {Style["Data from experiment 5B", FontFamily -> "Times", 
     FontSize -> 12]}, Alignment -> Center, ImageSize -> (4 + 4 + 0.5) 72],
   Row[
    {ListLinePlot[data1, opts], Spacer[0.5 72], ListLinePlot[data2, opts]}],
   Row[
    {ListLinePlot[data3, opts], Spacer[0.5 72], ListLinePlot[data4, opts]}],
   Row[

    {LineLegend[{Red, Blue, Green},
    {"x-direction", "y-direction ", "z-direction"},
    LegendLayout -> "Row", LabelStyle -> {FontFamily -> "Times", FontSize -> 12}]}, 
   Alignment -> Center, ImageSize -> (4 + 4 + 0.5) 72]}
 ]

My problem is that I have the wrong colors in the caption. How do I pick up the colors of the PlotTheme? I am using rows and columns rather than GraphicsGrid because I need to use the "Get Coordinates" feature using the right mouse click. Graphics grid does not permit this for individual graphs.

Answer

Use

colors=(("DefaultPlotStyle"/.(Method /. 
     Charting`ResolvePlotTheme["Scientific" ,  ListLinePlot]))/. Directive[x_,__]:>x)

to get the colors used in the "Scientific" plot theme. Then use colors as the first argument of LineLegend:

Column[{
 Row[{Style["Data from experiment 5B", FontFamily -> "Times", 
 FontSize -> 12]}, Alignment -> Center, 
 ImageSize -> (4 + 4 + 0.5) 72],
 Row[{ListLinePlot[data1, opts], Spacer[0.5 72], 
 ListLinePlot[data2, opts]}],

 Row[{ListLinePlot[data3, opts], Spacer[0.5 72], 
ListLinePlot[data4, opts]}],
 Row[{LineLegend[colors, {"x-direction", "y-direction ", 
  "z-direction"}, LegendLayout -> "Row", 
 LabelStyle -> {FontFamily -> "Times", FontSize -> 12}]}, 
  Alignment -> Center, ImageSize -> (4 + 4 + 0.5) 72]
  }]