Improve brewer2mpl accessibility

[Permafacture]

there needs to be some object that gives you quick access to nice brewer color maps.

1. sequential colors, with a default if you try to access more colors than there are
2. gradiants from brewer contrasting schemes (diverging, qualitative and wes anderson) to white (or black?) like in the zoning example.

Should have a good default and should make it intuitive to discover new schemes.