So I was looking at the first photo we got of Green Lantern, and it got me thinking.
Hal Jordan's costume is a construct of the ring, which harnesses green energy. So how could the ring produce the color black (or, in the comics, the white gloves) on the suit?
Technically speaking, wouldn't an all-green suit (like the EW cover) be more of an accurate presentation to what the ring is capable of constructing?
Easy explanation: iridescence. A butterfly's wing is actually colorless. It has many extremely thin layers that, depending on their spacing, diffract light differently to produce different colors based on interference patterns. As long as the green energy can interact with light -- it can, since we can see it -- then it can produce any color with a little help from physics.