The RLM 83 designation and colour name relationship is currently considered interpretive. What is known is that there was a color identified as 83 and that it was a dark green shade. This information is based on official paint samples, photographs, crash reports, comparative analysis with surviving aircraft, wreckage fragments, etc. (Smith and Creek, 1994, p.247; Smith and Gallaspy, 1977, pp.134, 136-137). Interestingly, Hitchcock (1983, p.13) was the only one to states that "Colour 83 has been officially recorded only as 'green'." Unfortunately, the source document is not indicated, though the presumption, given the publications subject, is that it was related to Bf 109 G production.
More recently (1999), Eagle Editions published a color paint chip chart utilizing material acquired from the late Ken Bokelman. In the preparation of his chart, they used as a reference a color paint card with a dark green paint sourced from Warnecke and Böhn archives that was identified as 83. Ken Merrick, long a colleague of Bokelman, shared much of their respective resources too and Ken invariably drew his current comments and insights from this new information and obviously supersedes his beliefs since the publication of his original (Merrick, 1977) and later book (Merrick and Hitchcock, 1980). Michael Ullmann also provided significant input into this research (Ullmann, 2000, 2002).
Work by researchers in Eastern Europe added important information, and hard data, regarding late-war colours (Poruba and Janda, 1997; Poruba and Mol, 2000). These researchers based much of their conclusions on four paint cards found at Prague-Rusin at the end of the war. Only two of these were identified on the back of each card: 76 and Nr.82. These matched exactly with other samples of these two colors. The other two cards were not identified, but again matched the known and accepted shades of 81 and 83.
Therefore, from what is known to date, the identity of color 83 is recognized and accepted as a dark green color. This is confirmed from various secondary sources, but most particularly primary sources such as the color paint cards from Warnecke and Böhn, and those recovered from Prague-Rusin which in both cases simply identified the color as 83.
Michael Ullman and native German has stated that his familiarity with the German Language and his full access to WWII official documents uniquely qualifies him to make these assertions:
Test Order E2-45/31
(Development and verification of camouflage for the Mediterranean Sea)
Report August 1943:
Alongside RLM 73 a "darkblue" colour will be use. Flighttest in the near future.
Report September 1943:
Using the camouflage pattern "Land" and "Sea" with RLM 73 and the darkblue colour 300/III suggested for introduction.
Report November 1943:
Closed with report dated 10. November 1943. Colour RLM 83 "DARKBLUE" with RLM 72 for Sea- and RLM 70 for landaircraft suggested for introduction.
Sammelmitteilung 2, dated 15. August 1944:
…on the dark shades RLM 72, 73, 75, 81, 82, 83 …. (no colour was stated)
Ulmann also mentioned that he has only seen one document earlier mentioning RLM83 and he then believes it might have been a typing error? This has then been wrongly "adopted" as one of the colors seen on land based aircraft BUT the newly found document states RLM83 was a color intended for aircraft operating over the MTO together with RLM70 or RLM72 and was stated "DUNKEL BLAU" (Dark blue) and intended for introduction at the same time as RLM81 and RLM82.
The RLM 83 was to be applied at unit or depo levels and not from factories, question is how much this color was ever implemented as in late 43-early 44 not much flying operations was conducted over the Mediterranean.
So even if the above is true am RLM 83 DunkelBLAU makes no sense for any land based aircraft