[Design] [D/f] Background for current week

[Davor Cubranic]

Coming to this way late, but how about colouring the column headers?
The idea is similar to how Mimi put a colour strip just above the 
hourly grid, but colouring the headers gives more room and can be done in 
less-saturated colours. There are two variations: colour just the "Week" 
button (it's currently aqua blue, why not make it carry some useful 
information instead?) or colour the individual column headers so that 
Today serves as the boundary.

Davor