What does the poem "Nothing Gold Can Stay" mean and how does it apply to Ponyboy, Johnny, and/or the story of The Outsiders?

asilly,

Robert Frost's famous poem "Nothing Gold Can Stay:"

Nature's first green is gold

Her hardest hue to hold

Her early leaf's a flower;

But only so an hour.

Then leaf subsides to leaf.

So Eden sank to grief,

So dawn goes down to day.

Nothing gold can stay.

explores the idea that happiness, perfection, bliss (all symbolized by gold) cannot and will not endure. The apparent paradox of line 1 is based on the fact that when buds appear in the spring, their first color is gold rather than green. 

The speaker also looks at the falling away from gold in nature, human history, and time. The leaf, humanity, and the day all begin in gold (bud, Eden, dawn) and decay quickly; perfection in any form lasts only an hour.

You can see in many characters the decay of their personal qualities or the fact that whatever qualities they do have will not last and will come to an end.