When you turn SmartTag off you are taking complete control of what parameters are tagged and thus recorded. In this case I’m selecting the fixture, modifying the colour attributes (which tags them - makes the background ‘blue’), then when I RECORD I turn off SmartTag which says ‘hey console I’m in charge I just want you to record the colour attributes I changed and nothing else, just do as I say and nothing more’. In the example of reprogramming defaults I agree it’s nothing to do with e.g. move on dark (this is just one example of where SmartTag usually helps the programmer), just by turning it off I’m in explicit control of what is recorded (and also In this case intensity was zero so SmartTag would have caused my colour parameters changes to be ignored).
Note that the colour attribute is by default set as ‘not separate’ (changeable in Setup). This means that if you adjust one colour parameter e.g. red, all of the colour parameters are tagged as it’s assumed that you want to create a certain colour and this requires all colour emitters to be recorded to recreate that. If you really only wanted to record the red emitter you would need to manually untag the blue, green, amber, colour wheel etc parameters (to make their background ‘black’) so they weren’t recorded. When played back, only the red emitter would be controlled, the blue, green etc would stay as they were. This is very powerful but can also be very confusing for inexperienced/basic users. Note that beamshape parameters default to ‘separate’ as it’s assumed that if you were changing e.g. the zoom you didn’t also want to record e.g. the gobo.
Some advanced programmers have SmartTag turned off permanently as they always want explicit control of what is recorded via tagging, especially if they are setting up a range of ‘partial looks’ on playbacks/submasters that they’ll use to busk with. If you’re programming a theatre stack then for many ‘normal’ users (myself included) SmartTag is usually on.
Note also when looking at your showfile I did it in PhantomZerOS which I started in FLX mode (not FLX S mode as your actual hardware). This gives me access to some more features, like the Source screen. This allowed me to see (but we already ‘knew’) that your fixture was controlled by ‘Default’ as the fader was lowered. I selected the fixture so I could see the parameters details, then on the Source screen I saw the colour parameters change to ‘D’ (and also saw the flick of B=G=255 in the DMX window) as I lowered the fader. Aha! Default is white (as we expected) and causing that flick in colour as you first reported. Reprogramming the default to R=G=B=0 was easy after that.
Happy programming - let us know how you get on and any other questions and we’ll try to help.