You'll create the background in three easy steps by importing your movie file and applying two effects to it. The Hue/Saturation effect helps give the footage a uniform appearance, and the Glow effect further stylizes the imagery:
1.
Add the City_Background.mov file to the Master Timeline at time 0;00.
2.
To give the City_Background.mov layer a blue hue, apply Effect > Adjust > Hue/Saturation to the layer. Use these effect settings:
Colorize (under Master Lightness): On
Colorize Hue: 0x220
Colorize Saturation: 45
Settings for the Hue/Saturation effect
3.
To add some radiance to the city background, apply Effect > Stylize > Glow to the layer. Use these effect settings:
Glow Threshold: 27%
Glow Radius: 18
Glow Intensity: .3
Settings for the Glow effect
The City_Background.mov layer with Hue/Saturation and Glow effects