I’m not sure if this was deliberate, but I find that a good model for understanding the difference between red and blue when viewing face orientation is “red shift” and “blue shift” of light.
When an object is moving away from you, its light creates a “red shift”. And when an object is moving towards you, its light creates a “blue shift”.

Similarly, face normals that are pointing outwards — towards the viewer — hit as blue, while face normals that are pointing inwards — away from the viewer — hit has red.