In case anyone finds this useful, I’ve added a new type of blending to the Mix node in the compositor. It’s a standard from Photoshop, called Soft Light. It’s particularly adept at color grading.
I used it (among other things) to try to achieve a stylized film-like effect from the renders from an animation. Click the low res for 720p HD:
Much more about it at harkyman.com.
And in case you’re wondering, this mix method is not something that can easily simulated or faked with other nodes and mixes. It’s pretty specific. And, once again, since it’s a patch, it would need support to make it to trunk. Let me know what you think.