Create sky gradient, BEHIND trees

[mikecazzx]

Is there a simple way to correct for a dull sky but behind a mess of trees?

I want to liven up the sky, but no effect the trees in the foreground. There are too many small limbs in the forest shot to mask them.

 

[Justin Kuhn]

color key maybe.

 

[VideoMaker]

There is a very easy way to do this in Vegas. On the track above your trees/sky footage place a blue gradient that goes from medium to darker blue from top to bottom. Then set the composite mode for the gradient track to darken. This will cause all of the lighter sky color to be replaced with the blue gradient. If you have any other light colors in your footage they may also be replaced so you will have to mask that out, but for most footage this is easy to do.