There are so many exceptions and variations to this that the collecting of military bands and colour parties is a whole hobby in itself. Suffice to say that the above vignette is attempt to picture a Colour Guard, with Captain, sword drawn, between two Ensigns followed by two Company Sergeant-majors (CSM's) with rifles shouldered.
The upper shot shows the main colour variations of the plastic for this set, basically the same as the Guards Band set.
The unit mounting ceremonial guard changes quite regularly, at Windsor castle for instance, it's every two days.
Useful Link for Guard's ceremony in London.
I also CAD'ed some tree 'flats' and took the Regimental Colour on patrol!
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