On the plot the geomagnetic local time in the spacecraft positions are shown as a function of the UT.
The UT (days and parts of days) is shown along the X-axis, the The geomagnetic local time (hours) - along the Y-axis.

On the plot concerning to the separate spacecraft the line is labelled by the simulative regions' symbols and colour.
On the summary plots the different colours are used for each of the 4 spacecraft:
The orbit crossections with the simulative magnetopause are shown as well by the "diamond" sign.