The calendar, especially in month view, displays an awful lot of information. Therefore it is crucial that the information can be read clearly.

Currently, I can only tune the colours for the events. Depending on the colour, the event text is shown in black or white. This decision is not always optimal, personally I would like some blacks to be white and vice versa. This may, however, be related to the choice of the font used to display the event texts. I seem to have no control over that either.

So to be able to improve the readability, I would like to propose a way to select the fonts used, and a checkbox to toggle black/white rendering.

White or black text color depends on the background color, and that can be automated. However it's a pretty complex problem. Fortunately, others have done extensive research on this, take a look.

Hence, a single black/white toggle for text color makes no sense. If you would really want to give total control to the users, then you should do like some other calendars do allowing for each categories to select the background color and text color manually.

Such color choice could be used indifferently for events and tasks.