Rated 5 out of 5 stars

A few days ago, one of my dreams came true! At last, the full event boxes were coloured instead of the ridiculous and barely visible little vertical coloured sidebar.(week view, of course)
And today, I'm desperate: the feature has vanished! Despite my updating to the latest release version (for both Th. and Light.), my calendars have returned to the default uniform colour, which makes it so much harder to spot at a glace the various categories of events (and especially important events).
I really wish there would be an option for us to toggle this feature, so boxes appear the way the do on Google Agenda, for example: fully coloured.
How come this feature suddenly appeared and then went away? Is there any way to get it back without fiddling in the Chrome files?

On a different note, one other feature I'm dreaming of is being able to have the location and description information appear in the event box if I want them to. When I have appointments in different places, I'd like to be able to indicate it clearly without having to type it in the Title bar, or having to place my mouse over to trigger an info bubble that gives me the details.
I enjoy and use Lightning so much, I wouldn't change it for the world. But at times, I wonder if developpers ever had a genuine paper calendar in the past, otherwise, they'd know what basic features one would need, such as indicating details of your appointment in clear, and being able to write important stuff in different colours, or even highlighting them. Having obvious flashy colours and more text space are basic functions of a paper calendar. They should be part of any virtual calendar to begin with.
But all in all, I thank whoever develops and maintains Lightning for their hard work. It's probably Thunderbird's best extension!

This review is for a previous version of the add-on (1.8). 

The event boxes should be colored using the color you chose in the calendar list on the left side. If they are fully transparent, then this might be an error with the Calendar Tweaks extension.

A bug report for your feature request is filed, lets hope someone steps up to fix it :)