On the plot the spacecraft geocentric distance are shown as a function of the UT.
The UT (days and parts of days) is shown along the X-axis, the geocentric distance (Earth's radii) - along the Y-axis.

On the plot concerning to the separate spacecraft the line is labelled by the simulative regions' symbols and colour.
The orbit crossections with the simulative magnetopause are shown as well, by the "diamond" symbol.
On the summary plots the different colours are used for each of the 4 spacecraft. In this case the SC names are shown by the corresponding colours.