I think there was someone who was asking how to do this a while back...   

Anyway, in a video that Smeagol made, he mentioned that for the opening scene, he changed the color of the blue bricks in the opening scene by keying out the blue and putting a black and white copy of the footage underneath.

I'm gonna show you how this is done with after effects.

It's actually pretty simple, here's how you do it:

Start off by importing your footage.  (File->Import->File).  I'm just using a still picture for this example, but an image sequence or video will work just as well.

Then, drag it to the "new comp" thing

Ok, so now it's all set up and ready to go.  Go to Effect->Noise and Grain->Remove Grain.

You'll notice a white square appears.  This is just a preview, and not the final output, so just switch from "Preview" it to "Final output".

Now, select the layer in the timeline and copy it (Ctl+C) and past it right underneath (Ctl+V)
It should look like this:

Select the top layer and go to Effect->Keying-> Keylight (1.2)

Take the color picker and click on the thing that you want to change.  (in my case, it's the blue part of the wall)

Now, select the bottom layer and go to Effect->Color Correction->Color Balance HLS

Play with the hue, saturation and lightness until you get the color you wnat.

And there you go, you now can change the color of the wall.  If it doesn't look quite right, play with the keylight settings.

If you know you're gonna be doing a color change like this, heres some stuff to keep in mind when you're filming:  Make sure that the bricks that you want to change are a different color than anything else in the scene.  If you look at the raw footage of that first scene, you'll notice that the wall is the only blue thing in the scene.  Blue isn't the only color you can use, but it's one of the easiest.  I'd say blue, green and maybe red are the easiest.

Anyway, I hope you found this useful.

Last edited by StanTheLegoMan (November 27, 2010 (10:20pm))