It's a long while since I covered Welsh politics in any detail - I was political editor of the South Wales Echo in the mid-90s - but I remember enough about it to know that the "rainbow coalition" idea between Plaid Cymru, the Lib Dems and the Tories was a complete and utter nonsense.
As Rhodri Morgan, now rightfully reinstalled as First Minister points out, there is a natural centre-left or "progressive" majority in Wales and any coalition which failed to reflect that would not have had the support of the Welsh people.
I suppose one can't really blame Plaid leader Ieuan Wyn Jones or Tory leader Nick Bourne for clutching at straws in the way they did, but I thought better of the Lib Dem leader Mike German. In the end he was unable to carry even his own party with him on the rainbow coalition proposal. He should quit.