The reflective nature of the outer layer of the Command Module can be seen in this fantastic photograph taken from the LM with the Sun directly above. The view is looking east over the lunar farside between craters Saha and Saenger. The lunar surface is reflected as light tones, and the dark portion mirrors the blackness of outer space.
From the mission transcript when the photograph was taken:
098:13:06 Cernan (Snoopy):
Get the Hasselblad, Tom, I’ll catch him when we come around.
098:13:08 Stafford (Snoopy):
OK, I’ve already got the thing out of it. [...]
98:14:44 Stafford (Snoopy):
This is wild, Gene-o. We’ve never seen anything like this before.
098:14:52 Young (Charlie Brown):
Pitch up. And get me out your front window. [...]
098:16:00 Cernan (Snoopy):
Got him out there?
098:16:01 Stafford (Snoopy):
098:16:02 Cernan (Snoopy):
Oh, beautiful. I can’t see him from here, but if I can’t...
098:16:11 Stafford (Snoopy):
I’m trying to match you, John. Should I be upside down to you, babe?
098:16:15 Cernan (Snoopy):
No, this is good.
98:16:26 Cernan (Snoopy):
Don’t tell me this damned thing isn’t working again. God damn it.
098:16:27 Stafford (Snoopy):
You can take off your helmets and gloves. [...]
098:17:07 Stafford (Snoopy):
OK. Did you get it?
098:17:12 Cernan (Snoopy):
They say f:8, but he’s awful bright out there.
098:17:24 Stafford (Snoopy):
You’re out a little bit too far. I’ll try to thrust in a little bit, but I - it really offsets me in pitch, as you can see. Can you thrust toward me?
098:17:35 Young (Charlie Brown):
Roger, I’m thrusting towards you.
098:17:39 Stafford (Snoopy):
Man, that fuel is going down like mad, too.
098:17:59 Stafford (Snoopy):
I’ll take care of the up and down, John.
098:18:21 Cernan (Snoopy):
Take some at f:8 and f - oh, you’re putting that up there. Taking you, John, babe, you’re a weird-looking machine.