yeah....Erich is absolutely correct about this K-4 being Blue 7 rather than Red 7.....it clicked for me too...yesterday! while trying to figure out Red Vs Blue ?........in this instance for JG 27, Blue numbers have a White outline (Ref : Blue 16) Red has a black outline (Ref : Red 23 'Ingrid')
...Sorry Rochie!...at least there is plenty of time to sort out Blue/White numbers....I will check my stash!!
Here is a good General reference profile for 'Blue 7' and the best 2 photo's.
Profile Source : Kagero Messerschmitt Bf109G/k Vol.III by Krzysztof Janowicz.
Photo Source: Luftwaffe over Czech territory 1945, JaPo, by Jiri Rajlich, Stanislav Kokoska, Ales Janda.
not sure about the yellow nose either...the area is certainly light in colour, but does not mean it is yellow. I also think the Rudder is a replacement in 75 grey/83 Green not 76 Blue/83 Green as shown in the profile, what do you think Erich?