From version 18.104.22.168, I included some new visual options for controlling the display of the Calendar. In particular, the background colour of the events area.
So, if you're wondering why your display isn't as colourful as it was before, then toggle the use of the Resource Calendar Colour, like so:
To change the background colour of the Resource:
You will probably want to check out the other useful options, such as "Group by..." as this is very useful in Month view when you have a great number of Resources displayed.