Symbology in the Lantern Corps emblems?

I'm curious about the symbology and meaning behind the various emblems of the Lantern Corps.

As I understand it, the Green is by far the oldest (both in- and out-of-universe), while the others are relative newcomers. Unless I'm mistaken, most were created during the War of Light arc, with the exception of the Star Sapphires, whose organization takes the symbol of the older sole-character Star Sapphire.

Some of these emblems seem to be basic representations (e.g. the Orange Lantern Corps symbol has a sense of gathering things together in a central place, which fits with greed, and the Black Lantern Corps points down, a direction generally associated with death), but others seem more abstract. Almost all feature central circles, and four (yellow, green, blue, and indigo) reference the basic Green Lantern design, with horizontal bars above and/or below.

The Green Lantern symbol itself is obviously a representation of a lantern, and I've also heard arguments that it represents an exertion of willpower (a circle forcing two lines apart, or two lines containing a circle).

Have there been any official comments by the artist(s) who designed these symbols about what the various designs are meant to indicate? Are they meant to be representations of the emotion they represent (and if so how), or are they simply abstract symbols meant to look like equivalents of the older Green Lantern symbol?