My first guesses: ....Jenova?
I have a face few would be proud of, --> ugly thing
But a certain granduer nonetheless. -->duh
Few, if any, know my purpose, --> few people know, what Jenova is
And little it must seem, --> At first it looks like it's not very important
But of great matters I surely handle, --> Later in the game, Jenova becomes more important
Between the green and the white. --> the colors of the Jenova parts
