In the color-coded emotional resonance of the DC universe love is violet and violet is the color of Star Sapphire and her star sapphire gem. It turns out that her gem can be split up and assigned to whoever is worthy or thirsty enough. Hand out enough gems and you’ve got yourself a corps. It worked for the Green Lanterns.
References: [comic-network.fancom.com: Violet Lantern Corps]
[wikipedia.org: Star Sapphires]
not[crystal]
Metahuman Database 