Thanks everyone, that's quite an interesting read and it clears up a lot of things for me. I had to read all this a few times to understand because I don't know the Atari 2600 system very well or analog television sets and I'm trying to wrap my mind around this entire concept. I'm more versed with the NES which doesn't seem to be as crazy with the video system. Even though you have to deal with the analog television set which I believe is about the same back in those days.
Although, these screen shots were also throwing me off about what the resolution could be.
Here is the MESS screenshot at 176x223. If you trim some of the black off it results to being close to 160x192.
Here is a screenshot from PCAE-WIN. Stella appears to output a similar resolution.
I do understand the vblank and hblank concept well enough. It's the color clocks that I don't quite understand. From what you said, 4 color clocks can equal one pixel and below you said one color clock can equal 1 pixel. Even though I know now there is no real pixel on one of these analog television sets. I'm kind of getting the picture that a lot of objects onscreen are of variable size. And that for larger television sets or different sizes, the video screen is scaled to fit. I wouldn't know the technical terms for this, only what I have observed by eye.
I still don't completely understand the entire concept. But soon I'm going to try and make a demo to see how it all works. But it may be awhile since I'm involved in a NES coding project right now. Happens to be my first one, as a matter of fact. So, I'm learning there as well. 6502 is coming easy to me, it's controlling the hardware that's a real battle.
And yeah, back to those screen shots. Neither one of them looks right to me. I used to own a Atari 2600 and also I watched a couple videos on YouTube and some of the commercials that showed a game being played, even if a very short clip.