Yes the spark is bluish.
Mike I had a remote shutter and I think it was 3.5 seconds.
The magneto was driven by a electric drill so if you look closely you’ll be able to count multiple sparks.
I used a microscope lens so the DOF is really shallow.
I have some thoughts on using my Cognisys StackShot rail to take multiple shots while the magneto is firing sparks, hopefully get better focus.