General Motors is adding two rather businesslike color choices for potential buyers of the Chevrolet Volt extended-range plug-in: Brownstone Metallic and Ashen Gray Metallic.

Chevy will offer the two new colors on the 2014 model-year Volt, which folks can start ordering next month. The addition brings Volt's color total to nine, including Black, Crystal Red, Summit White, White Diamond Tricoat, Blue Topaz Metallic, Silver Ice Metallic and Silver Topaz Metallic. We forgive you if you lost interest there, since they all kind of sound the same. Except Black. That's nice and straightforward.

Last week, Chevy said that its Volt fleet collectively surpassed 150 million electric miles. During the first quarter, GM sold 8,244 Volts during the first quarter, up 8.4 percent from a year earlier. Volt sales tripled last year.