@Babene1 the base MagicMirror calendar module does not provide a way to affect styles for ‘today’
You may be able to do this with css.
Looking at the code, it adds a class name ‘today’ to the events for today
So in custom.css
.calendar .today {
color:red;
}
that colorizes the symbol and time
for the title
.calendar .calendar .today .title {
color: red;
}
for both
.calendar .today , .calendar .today .title {
color: red;
}