The last illustrative element for the image. There's probably still composition tweaks to make, but this is the color for sure, I'm really happy with it. The angles of the Fortress of Solitude create the shape of the Phantom Zone prison Zod and Co. were trapped in.
Now let's put it all together...
There it is! Now keep in mind that the final painting won't be quite so saturated in color, but it's a great guide for me to mix the paints for the airbrush. But yeah, I think this one will be pretty cool, it's themed out in blue red and yellow, and I think it will blend better in reality, versus this digital version.
Now it's time to draw it.