Rated 4 out of 5 stars

NICE!!
Seems to work well.

The only thing I would like is the ability to adjust the colours either through a menu or a note about where the colour is set.

This review is for a previous version of the add-on (2.0). 

Calendar Tweaks 5.0 allows user customization of 'Today' and 'Selected Day' colors (header background color, day box background color, and border color).