well, just like everything else in the movie, like sound, music and camera motion, color sets the mood for the scene.
Matrix has dark green tint and really dark. Sort of early digital green monochromatic color, and gives off the mood of depressing computer age..
but then Tron has really distrinct color is a bit blue and white, and story is set similary to Matrix, in digital world, but only in TRON, unlike matrix, everything is sterile, clean, precise. Like a perfect running machine.
the "natural plane interior" (which is still has carefully chosen color scheme ) that you're referring can be seen in comedies, where director wants us to relate to main characters and see the characters as part of our world..
Thats just my two cents
There are waaaay more experienced indietalkers around here who will either agree or disagree.
But imagine if Inception had just plain everyday apartment walls, or typical office settings.. Even spinning hotel room would have those ugly blue/green rugs in the hallways, and crappy paintings on the wall...
But instead you get this
BAM!!! Full on epicness. Black. White. Dark brown. Freaking sexy, thats what that is. It sets the mood like these guys don't f&ck around. This is serious business.. none of this Bob Ross "Happy Cloud" sh*t.
Imagine if you were watching Inception. Bullets flying by, tension is high! Its a dream in a dream in a dream, dreamed by a squirell, and then there is this on the wall:
That would ruin my movie experience. Too distracting.
And thats why studios spend not 10,000 on their movie, but much much more