For 3D compositing:
I'm surprised no one suggested Flame or Inferno, which I believe are the top of the line. Smoke is nice too. It's a VFX and NLE in one. All of these programs have jumped from one company to another. Right now, it's Autodesk. I believe they'll give you a fully functional version of at least Smoke to learn. The new Smoke is only available for Mac, unfortunately.
I had never even heard of Nuke until now. Shake came and went, it seems. I have not checked the latest version of After-Effects but back in the days (5 years ago) it was more of a motion graphics/2D compositing software. I think it's a great program though, affordable, very easy to learn, user-friendly GUI, lots of effects and plugins, and support for render farms.
For 3D modeling/animation:
I'm not too much into this, but I would go for Maya because it is the easiest one to learn, it's a standard in the industry, and you could make something that looks like it came out of Pixar with it, seriously. Just don't expect to be able to do it for at least 10 years. Also, I think they can give it to you for free to learn but with limitations.
Coloring:
DaVinci seems to be the standard at the moment.
CONCLUSION
Maya + Flame (+ lots of expensive hardware) and you should be all set.