What does the color blue represent in the collection, Bluets?

The color blue is by far the most complex symbol in the poem, particularly as it does not symbolize any single thing; rather, it is the crossroads within which all other symbols and themes meet. There are at least three levels of meaning attached to the color blue: first, its identity as a physical object or wavelength of light; second, its cultural associations and connotations in the world; and third, its physical and symbolic place in the speaker’s own life.