I don’t understand what “ps ho lstart 1” and how to “configure highlight color”

The first parameter consists of the h and o options.

Very old Unix commands used to handle options without a leading dash (this can still be seen in tar). Also, the ps command evolved differently in BSD and SysV Unix families, both variants growing different options, and the Linux ps accepts both kinds of options – distinguished by whether they are prefixed by a dash or not. In this case, options without a dash are interpreted as "BSD" options. (Nowadays, BSD ps accepts a dash too.)

DESCRIPTION
       This version of ps accepts several kinds of options:

       1   UNIX options, which may be grouped and must be preceded by a dash.
       2   BSD options, which may be grouped and must not be used with a dash.
       3   GNU long options, which are preceded by two dashes.

The two options are:

       h      No header.  (or, one header per screen in the BSD personality).

       o format
              Specify user-defined format.  Identical to -o and --format.

This indicates that the second word – the one following the o – is an argument to the o option, and contains a list of columns to display. In this case it specifies only one column, the LSTART field.

Finally, the third word doesn't belong to any options, so it is interpreted as a PID – specifically, process ID 1 is the init process, which has been running since the system was booted.

PROCESS SELECTION BY LIST

       123    Identical to --pid 123.

The result is that the command shows one column of information for one specific PID.