I've certainly seem monochrome photos, where the interior of early 1940 and BoB period '109Es appears to be RLM02, with a darker coloured seat. It's difficult to say if the seat (in these photos) is RLM66 and, on some 109Es I've built, I opted for a shade nearer to RLM74, just to provide some contrast.
I've also seen preserved (un-restored) colour cockpit shots in overall RLM 66, and some as described above, and some overall RLM 02 !!