Adjusting color seems simple, but it's really not. It's both science and art.
There's several great options, such as:
- basic
VirtualDub (with Colormill plugin)
- somewhat complex Avisynth scripting
- the DaVinci pseudo-NLE
- and quite a few others, both suggested software, and lousy software -- so be careful!
All of them require a learning curve, but can do what you want. For color correction, I really don't think any of them is easier than the others.
Most video/NLE software requires an export to get a new clip. Merely "saving" the project saves the timeline information, not a new video. I'm not sure if that's what you're asking here?
As far as the "getting 2 clips" issue, it sounds like you want something with a timeline, to add multiple clips, and adjust each independently?