When creating a new calendar event it is not clear to which calendar it is assigned (one should carefully check the last line everytime). Sometimes I happen to create a Private event in a Public calendar.
To fix that, I suggest that the New Event background is set to be the current Calendar color.
The rule is that if you are in the Calendar section, the new event will be created in the calendar that is in focus - the one you are clicked on. So if you are clicked on a public calendar, that is where it will be created by default. If you are in another section of eM Client, usually it is created in the default account calendar.
But I like the idea of color coding, especially for when you are not paying attention. 