If you prefer your 3DS in aqua blue, you'd better act quick! The official 3DS hardware pagesays that production for the system's Aqua Blue color variation will be ending shortly.
Aqua Blue was one of the system's first two colors, launching alongside Cosmo Black on February 26, 2011. Cosmo Black appears to still be in production, as it does not have the same notice.
Other variations at the official site include Flare Red, Misty Pink, Ice White and Cobalt Blue.
Source: http://andriasang.com/con0ze/3ds_aqua_blue_productio
No, Aqua Blue!!!!!!!!
Edit:This might be for Japan only, Europe and North America have not mentioned any plans to discontinue Aqua Blue.