Hello,
Since the UI change in Version 8, the calendar has been very hard to read on colors that previously worked great.
I was using the purple, and now the next is a faded gradient rather than a crisp white or black, or some other contrasting color.
Is there a setting, or is this a bug? 
I changed the color of my calendar events to a lighter color in the Properties section, it helped, but still not great. Would also like to change the font size.
I agree,the color is awful.I can’t read any of my events.The colors in the properties help a little,but now it looks like a clown calendar.I hope there is a fix for this.
I also have white on purple for one of my Google Calendars. I updated to version 8 tonight, and you are completely correct. White on purple is completely unreadable.
Ok, I right-clicked on that calendar in the calendar list on the left, and selected Calendar Color. I changed it to a dark purple, and now I can read the text again. Hope that helps others. If eMClient is reading, might be better to use black text on the light purpose background.
Another vote for the ability to change the Calendar events font size!