MrCeriusFor multiple reasons.
1st, too many options. The more options you give, the more difficult a project becomes. Margins are already slim. Who want's to pay more on every pen because we added more options?
2nd, green is a difficult color to produce consistently, and it's hard to photograph well. If we sold green, we'd have a hundred emails. "Mine doesn't look like the picture", "My tip and body don't match", "I thought it would be a different shade of green..."
This is a MassDrop, not a "I want 50 different custom options, all at a great discount Drop!"