According to Jim Carter's, Mariner is one of the darker shades of blue, and Transport is a medium blue.
If any of you haven't seen this already (and if you're still interested), Carter's catalog has a separate section for deluxe cab interior items, which I missed the first couple of times I looked at the catalog online (I don't have a print copy). It explains that in mid-54, four different two-tone interior packages were made available. See
this catalog page and the next.
If the blue and green are two two-tone combos, and the gray/maroon is a third, what is the fourth??? Did the buyer have a choice of interior colors, or was the interior dictated by the choice of exterior color to insure coordination?