Karina,
Distant lightning is often orangey and reddish in colour perhaps due to the haze and dust that can be kicked up at that time of the year. The city lights reflecting on the cloud bases can also impact colouration.
Overhead, you are looking through a different atmosphere so differeing wavelengths filter through. This is just a basic way of looking at it but if there are other more technically minded people with some better explanations I would certainly like your thoughts posted here.
Regards,
Jimmy Deguara