We just covered Lumia 920 going on sale at EE and Phones4u (EE contract) though official dates given by Nokia were 2nd of November. In case of Lumia 820 Nokia has mentioned a launch date of 7th November. If you wish to know about the colors and carrier availability then check after the break.
According to Nokia, Lumia 820 will be sold in Black, White, Red and Yellow editions. The pre-order links for the carriers are given below. Great thing is that almost all the operators are offering “Free wireless charging shell” and “Free wireless charging plate” with Lumia 820.