Apple has retired all but one Smart Cover and one Smart Case for its older 9.7 inch Apple iPad models; with Apple still selling the Apple iPad 2 as an entry-level version of its tablets, those buying that model have just the Dark Gray version of the two covers available to buy. Once Apple Stores run out of stock on the Smart Covers and Smart Cases for the older iPads, you will be forced to switch to a third party producer of the protective covers...
Source: http://www.phonearena.com/news/Apple-leaves-just-one-version-of-its-Smart-Cover-and-Smart-Case-for-older-models_id48958
Source: http://www.phonearena.com/news/Apple-leaves-just-one-version-of-its-Smart-Cover-and-Smart-Case-for-older-models_id48958