1) I want Spectre to read like Dart code, these can all be specified inline with the variable definition.

Requirement: The default values are specified in the variable definitions in BlendState.

2) I like the XNA default values. Expose them from the GraphicsDevice, also expose the _default_ blend state from there. Use that blend state in the _reset method.

Requirement: The reset method must use the pre-created DefaultBlendState and not respecify all the values.