Ok, so assuming that what we are looking at is pre-painted components. Which if the Ullmann illustration is correct can be a reasonable assumption given the tonal differences of the individual components seen on the aircraft in the photo and how they then translate differently to the apparent official Ullmann RLM splinter pattern...
The areas which to my eye are really causing issues, are in fairness areas that have been meddled with at unit level. In which case the rule books and guidelines go out of the window so to speak. For example the tail area where the red band and older swastika style has been adapted into the newer style and as Ed has pointed out the overpainting of the factory codes which believe it or not and rarely visible on black and white war time photography occurred to varying degrees of application on 100% of LW aircraft photographed in service with a frontline unit.
Linked is a diagram I have created showing what I believe can be seen in the photo posted by Dénes:
here
The tonal differences between the individual RLM61/62/63/65 splinter colours in my opinion can be explained by the extreme exhaust staining and the differing paint batches of the same colour seen on different components. The differing colour tones between the same individual RLM colours clearly adhere to the panel lines of the different components... For example the forward cowling components, which if we follow the Ullmann illustration should be the same paint colour as seen on the fuselage directly below the canopy.
The blue segment in my diagram is clearly an after factory, unit applied addition intended to cover the factory code (pre-war green) and the red segment is another addition at unit level that doesn't appear to follow the official Ullmann Ju87A pre-war splinter pattern, but maybe intended to allow the more important areas of the black unit code to stand out against the darker colour tones of the original factory pattern. In my opinion the red segment is a slightly lighter (in application) overspray of the pre-war grey colour that is allowing much of the underlying darker colour tones to show through thus making it appear darker to the same grey colour seen on the rudder and other sections of the aircraft.
Personally I believe what we are looking at is simply and as expected the normal pre-war RLM61/62/63/65 B (or A?...) splinter pattern for the Ju87A, but with the usual unit level meddling that was necessary to adapt how the aircraft was coded when it left the factory to what was required code wise at unit level...
