Hi,
Information from the publication
Kampfflieger Volume 2 by Smith & Creek (Classic Colours) states that on 15 August Luftflotten 2 & 3 co-ordinated attacks with Norwegian based machines from Luftflotte 5, the latter comprising a force of some 72 Heinkel He111s from both I. and III.Gruppe/KG26. They set out from Stavanger/Sola airfield heading for RAF airfields in the north of England, particularly Dishforth and Usworth. The incoming German aircraft were intercepted by RAF fighters and eight of these bombers were downed. There is no confirmation in that book which Gruppe the machines were lost from.
Bomber Units of the Luftwaffe Volume 1 by de Zeng & Stankey (Midland) advises that III.Gruppe/KG26 had some 26 machines available on 13 August, comprising Heinkels of both H-3 and H-4 sub-types, and confirms the Gruppe's attempted raid on north east England on 15 August, stating that the Germans lost seven of their number from this Gruppe, the force having been intercepted before reaching the English coast. This publication says that III.Gruppe's targets were Dishforth and Linton-on-Ouse; I.Gruppe had 29 machines out of 30 available on 13 August and its (main?) target on 15 August also appears to have been Dishforth. The information merely says machines from I.Gruppe were turned back by RAF fighters - no losses are mentioned.
I would suggest that you are correct in your thinking that if it was the case that the machines lost were from one particular Staffel, then there would likely only be a handful of aircraft remaining to that Staffel. If indeed 1H+FS was one of the aircraft lost, then being an 8.Staffel machine, its I/D letter 'F' would, in normal practice, be coloured red, and possibly accompanied with a white outline to mark it out against the dark green colour scheme.
Rolfe & Ketley's
Luftwaffe Emblems 1939-1945 (Hikoki Publications) seems also to suggest that the III.Gruppe's unit emblem would have been black detail set against a red background, although personally I find that a little strange, as III.Gruppe's I/D colour was yellow; consequently, because I would have expected the background to the shield to have reflected the Gruppe I/D colour (yellow), I'm inclined to think that the captions to these emblems in that book are perhaps transposed wrongly, one against the other.
It is my belief that more often than not, the propellor spinners would - either completely or partially - match the Staffel I/D colour, in this case red, and the background to the unit emblem would more likely have reflected the Gruppe I/D colour, in this instance yellow. This was what would probably be accepted as standard practice, but often there were anomalies, so proceed with caution.
If you require some additional guidance regarding codes and colour I/Ds, this site
www.luftarchiv.de is very helpful. It is in German, but once you see the coding grids, most things should perhaps become clearer for you. Once you're on the site, follow these selections below from the left-side menu to reach the appropriate page, then scroll down on the last page and you'll see the charts:
Luftfahrtindusrtie, Kennzeichen, Motorflugzeuge, 1939-1945.
Hope this is useful, but feel free to come back and ask if you have further questions.
Regards,
Paul