Customise the background colours of columns in your google calendar.
GCal Column Colours is a tiny nifty plugin with a single purpose: To give customised colours to your Google Calendar.
This version gives your weekends a light grey background and gives the 'today' indicator some colour.
Note that this is version 0.1 and may have some bugs.
Future versions may be more customisable and may work for languages other than English.