Inspired by BladeJunker's thread, I decided I wanted to try and make a mockup within Atari 2600 restrictions. If this isn't considered true pixel art (and I can see why it wouldn't be) go ahead and move it to Low-spec or something.
You and me both on where to put 2600 stuff, hard to say where to file it?

The mockup is inspired by Strategic Simulations' AD&D games where map navigation is on a first person view, and baddies walk up to you before you go into combat (which is a separate screen which I haven't tried to draw yet).
I'm not familiar with the inspiration so I'll have to look into that. I will say that separation of activities into different screens or modes is something I can recommend for any 2600 game since the lack of drawing units is not unlike a polygon limit in that isolation and concentration of rendering power to one focused subject matter will reap rewards.
I'm hoping to make sure the restrictions work out so hopefully BladeJunker will comment here.
The restrictions look to me that they will work, 2 line kernel Playfield render with per scanline color changes. You're a lot more conservative than I was when first started trying this stuff out, I went overboard so many times.

Not a bad choice clipping the background for the sake of changing the monsters color scheme as its a good method to get familiar with. However you're already so trim with your rendering use you could probably use a mid-line color change within the middle 16 pixels of the Playfield and preserve most of background on the sides and use any of the movable object sprites to fill in the remainder of your background clipping losses.
Another option is to render the monster using both Player objects as an overlay stretched to maximum width, if you don't need any Missile bits within that vertical zone this would completely avoid any background clipping issues. Since your backgrounds are mirrored using Player objects for the monster would avoid the extra costs of drawing an asymmetrical Playfield to insert the monster tile made of Playfield pixels.
Designed this so that the sky color can change and still look alright on daytime sky colors (also I just realized that I didn't adjust the colors on my desktop computer so the colors will most likely change).

Sounds good, plenty of color shifting routines on the 2600. As far as the colors being off its the same old story of NTSC or Never The Same Color, most posts on AtariAge tend to vary between emulator results and changes needed when running on actual hardware plus NTSC and PAL differences. Manual tweaking at actual run time isn't so bad since we're not using that many colors to begin with.
This was fun to do. I'll probably have to make improvements in readability for the armor.

I think I'd recommend trying for more iconic readability as large chunky pixels turn into noise very easily, might want to try one color first for composition and then consider color zones afterwards with some tweaking. I saw some good examples by Pac-Man-Red over at AtariAge on utilizing per scanline color changes, he's quite good at drawing sprites in general and he often draws within a 2 line kernel resolution. Here take a look.
http://www.atariage.com/forums/topic/169238-free-sprites-for-the-taking/Not sure what I want to do about the HUD at the bottom. Not even sure what I want to put there to begin with since imitating the full statistical gameplay is out of the question.
EDIT:

I'm looking into HUD/stat related limitations soon so I'll post that under my discussion asap. You're right to be doubtful about full statistical tracking as the 6502 CPU is limited in speed but any kind of turn based gameplay should help so it only has to do 1 or few things at a time.
Anyway looking good in my opinion.
