[Maciej Góralczyk]

My take is that 210129 was repaired after the belly-landing with Köhler, and then was re-marked (note the area around the number seems to sport more fresh RLM 76 than next to it) with 'Red 9' (the number is fairly dark but not black and doesn't have an outline as a black number of 10. Staffel or a yellow number of 11. Staffel would have; besides, the yellow of the fuel triangle shows up as a very bright tone on the photo from Christer's book, whilst the number stays darker - unless some magic with colour filters - that cannot be excluded - happened here, it is simply the effect of using panchromatic film) and assigned to 12. Staffel, with which it was damaged again and left in the condition we can see in the photos, with the loss/damage record not preserved.

As for the Geschwader ID band, the prescribed colour for JG 54 was light blue. Period photos show more examples of such bright bands - see the photo of 210037 mentioned in one of previous posts, or photos of IV./JG 54s Fw 190 A-8s in JFV 13/II, pp. 311, 387, 415