I believe you, I just honestly never heard of it. And I just looked up on RealOEM for a 2006 E53 and the only colors are as follows (on the "covering inner" section):

-Dark Poplar (Dunkel)
-Light Poplar (Hell)
-Smoke Grey Poplar
-Titan Silver
-Graphite Metallic
-Natural Poplar (maybe this is yours?)
-Mahogany Maritime (definitely not yours)
-Cosmoschwarz (Piano Black)
-Imola Red
-Lemans Blue
-Savana Beige

That pic you posted honestly looks like Dark Poplar, but I never had Dark Poplar so I couldn't say for certainty. See if you can pop off a door panel trim piece later and grab a part number from the back of it and post up a picture of the trim. But honestly I've never heard of nor seen Maple Anthracite, and if its different than the ones listed on RealOEM it truly is a rarity because I can't find it.

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2018 Ram 2500 6.7L Cummins 68RFE
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2013 X5 35D (CEO's) - Born on 5/17/2013 -
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