Jagdkommando...
Speaking in general terms, up to 1938 most cockpit interiors would have been finished in RLM Grau 02, with the instrument panel painted in RLM Schwarzgrau 66, in order to prevent dazzle (L.Dv 521/1, 1938). In 1941, instructions were given to paint the cockpit and canopy frames in RLM Schwarzgrau 66 also (L.Dv 521/1, 1941).
With the war stretching out longer than the Germans expected, restrictions on materials required that simplifications be made to the painting process, and by the time Arnim Faber presented the RAF with his example of the new Focke-Wulf Fw190A-3 on 23 June, 1942, the interior of that machine was almost entirely finished in RLM Schwarzgrau 66.
I imagine, therefore, that the same processes would generally apply all Luftwaffe machines, including the Fieseler Storch, and that it would be dependent on when exactly the machine you have in mind was built - the Fi156A-0 pre-production and A-1 versions began to be delivered from the Spring of 1937, the 'B' sub-type was never followed through, being largely intended for civilian use, and the first examples of the main 'C' sub-type started coming off the production line in 1939. In theory, even a pre-1938 built Storch could still be sporting the RLM Grau 02/Schwarzgrau 66 combination of internal colours well into the early war years if it managed to survive that long, whereas later built machines would likely have had the overall RLM Schwarzgrau 66 finish.
Luftwaffe Colours 1935-1945 by Michael Ullman (Hikoki publications, ISBN 190210934-1) will provide you with the above information in far more detail, and the various changes that occurred during the war, if you're interested in checking further... good photos, too.
Regards...
