503 is to be the best connected Asha of them all, with 3G, Wi-Fi and Bluetooth 3.0 radios, plus a dual SIM version. Moreover, the Asha 503 and 502 fit in 102.55 mm x 60.55 x 11.5 mm bodies with about112g of weight, and feature this funky dual-shot body design we already showed you. The Nokia Asha 502 is supposed to come in 6 candy colors - black, white, yellow, red, green, and blue - so we'd assume the same for the Asha 503, too. The handsets are supposed to come for about $110 and below, which would be pretty decent for the best-equipped Ashas out there...
Source: http://www.phonearena.com/news/Nokia-Asha-502-and-503-specs-leaked-3G-and-hit-apps-arrive-to-the-series_id48503
Source: http://www.phonearena.com/news/Nokia-Asha-502-and-503-specs-leaked-3G-and-hit-apps-arrive-to-the-series_id48503