How to give a different color?
The raw data is a list of 1400 coordinate points. The data can be reshaped as 5 individual lists of 280 coordinate pairs.
Clear[data]
Get["https://pastebin.com/raw/AVFwHkC8", "Data"];
newshape = ArrayReshape[data, {5, 280, 2}];
Now ListPlot[newshape]
will give a different color to each curve.
How to superpose the curves without distortion?
An approximate way is to shift each curve up or down so its 50th data point, say, lies on the x-axis. Plots at different scales show the 5 shifted curves happen to cross one another at points near x=49.54.
shifted = # /. {x_, y_} :> {x, y - #[[50, 2]]} & /@ newshape;
ListPlot[shifted, PlotRange -> All]
ListPlot[shifted, PlotRange -> {{20, 85}, {-1, 1}}]
ListLinePlot[shifted, PlotRange -> {{40, 65}, {-0.025, 0.025}}]

The last plot hints at the amount of distortion that would be required to really superimpose the curves throughout the region.
Sensitivity
As it turns out, choosing the 50th data point of each curve worked fairly well. But what if another index had been used? We can use Manipulate
to test other values of the index like this:
Manipulate[
shifted = # /. {x_, y_} :> {x, y - #[[ndx, 2]]} & /@ newshape;
GraphicsColumn[{
ListPlot[shifted, PlotRange -> All, ImageSize -> Small],
ListLinePlot[shifted,
PlotRange -> {{40, 65}, {-0.025, 0.025}},
ImageSize -> Small]
}],
{{ndx, Length[shifted[[1]]]/5, ndx}, 1, Length[shifted[[1]]], 1}]

We can change the value of the index to see how that affects the overlay of the curves.
Toward an automated method
It may be possible to use the manipulator on several different datasets to develop a method of choosing the index that determines the amount of the shift. For instance, it may be found that 20th data point is a good choice if the curves are to overlay between x=20 and x=40.
Another strategy may be to shift the curve so that some data point near the middle of the valley between the first two peaks lies on the x-axis.
Combine PeakDetect
and Position
commands to find the indices for the peaks and take it from there.
PlotLegends
The questions on this site contain many good examples of using PlotLegends
. If you have a some specific case that is not working for you, please post the troublesome code in a new question.