When my commute was longer and part of it on a two lane county highway (no shoulder, narrow lanes) I would run side facing lights and use blue flashing for those. Reflectors only work when light is hitting them and I want to be visible long before that. I picked blue because why not? They aren't super bright, just enough to make me visible at night. My rear facing light has a blue flashing and red/blue flashing function. I'll use the red/blue during the day if I'm on the highway just to catch attention from a longer distance but at night I use the red only.

And for the record, I'm certain that website's references are outdated. It says it's illegal in my state to use blue lights but I recently looked it up and there was no mention of blue; only restricting the directional use of white and red (white facing forward only and red facing rearward only).