Nintendo added yet another color to its current roster of Nintendo 3DS colors. The Cobalt Blue 3DS went on sale last March 22, 2012 in Japan, making it the sixth color variant. Let's see now: there's Cosmo Black, Aqua Blue, Flare Red, Misty Pink, Ice White, and now Cobalt Blue.
This Cobalt Blue version uses a much richer blue tone, unlike the Aqua Blue 3DS, which was more of a blue green shade. The new color remains a Japan-only exclusive for now, but there's always a good chance this might head for other regions soon.