Red, White and Blue

I saw this planter for sale at a local garden centre. They were selling the red, white and blue planting as a celebration of the Olympics. Doubtless it was previously for the Queen's 60th Jubilee. Whatever it was for it looked just too good to ignore, and has found a home on my garden terrace.

All I need now is blue and yellow arrangement to support the other half of my allegiance! Any guesses why?