I note a few things here.
First you say, 2 light sources. Soft blue from left, and sun coming up from the right. And the inks seem to indicate a strong rim light from the back right. As well as main light source from upper left. Similar to as you noted, although, I would say the rim light would require the yellow light to be behind them.
But then you have the sunrise coming from back left. that doesn't make any sense. That's 3 light sources.
That yellow rim light now is not on the buildings, cars, or anyone but the extreme close. so I dont know. streetlight? headlights? I want to see it on the ground as well to show where its coming from.http://www.bbeled.com/image/projects/so ... sa/1.2.jpg
A slight fog might add mood, as well as let you show the light in the atmosphere as well.
You could still go sunrise. But it needs to be hitting the tops of the buildings most. The building directly behind the girl would be casting a strong cast shadow. and the sunrise visible in the bg needs to change.http://www.acadiamagic.com/panas/acadia-sunrise-p01.jpg
If the sun is to the far right, only the slightest if any orange/yellow/pink would be visible there.
Did you draw it too?
I'm not sure it makes the best cover art in general, honestly. Its not very engaging.