Anamorphic Lens Flare Implementation

I want to add support for anamorphic lens flare effect in my engine.
I was wondering if somebody can share main implementation ideas.
How did you implement it in your studio?

In particular:
1. I'm interested in a screen-space approach. I don't want to splat sprites on top of the rendered image.
2. If I want to favor blue tint over other colors, how should I take into account pure red and green light sources? (second image below). In the first image, the explosion is not blue yet the flare has a blue tint. This is more a …