Those who read my blog know that I don't have a standard colour scheme because I try to colour candidates/parties on the basis of what serves as their colour in their country. So I use black rather than blue for the Austrian and German right, green for PASOK, pink for the PS (but red for the PSOE or the Walloon PS) or orange for the NDP. In general though, my base colours would have to be:
Trots/far-left
Communists/democratic socialists/Eurocommunism/Radical left
Social democracy/modern socialism/left
Green parties/ecologists/environmentalists
Latin Radicalism/social liberalism
Classical liberals/libertarians
Regionalism/separatism (varies)
Agrarianism/Scandinavian Centre-liberalism
Centre-right
Certain Christian democrats (UDF/MRP variety)
Conservatives/liberal-conservatives/right
National conservatives/Social conservatives/Reactionaries
Far-right/right-populism/fascism
Anarchism/anarcho-capitalism
I basically go by these standards with little variation.
