Eluga A3 does have 3GB LPDDR3 RAM.
Panasonic Eluga A3 is available in 2 colors - Gold & Mocha Gold.
Panasonice Eluga A3 comes with 5.2 Inch HD IPS display with 1280 x 720 resolution which produces 282 PPI resolution. It has Asahi Dragontrail Glass which provides protection against scratches etc.
Yes, Panasonic Eluga A3 does have support for the OTG.
Yes, Panasonic Eluga A3 does have a hybrid sim slot.