Just a heads up: It is more useful too keep on project in a single thread that way everyone can follow the progress easily and avoid clutter in forums.
Here is a quick paint-over I did.
I used the same number of colors you did in your original, but I changed them. You had 3 nearly identical blacks and 2 very similar whites. When colors are that similar at this scale, they aren't helping you to add any information at this scale.
I adjusted some shapes, such as the pauldrons to be more interesting. I shifted the pauldrons forward because the left most arm (his right arm) appeared to be dislocated so far from the body.
I also shifted the vertical line in the visor forward one pixel to make it appear he is not facing straight at us.
I made the pose slightly more interesting by moving one hand forward onto the hilt of the sword.
I extended the tabard downward to give it more presence and to delineate all the grey.
Some of the places where you used black I used brown.
If you look at your pallete, you will see it is mostly blacks and whites. While it seems sensible to use lots of greys for steel, steel actually reflects a lot of the colors around it. For this reason, I used very de-saturated blues instead.
I also added a scabard to hint at the sword the knight would be resting his hand on.
Oh, also a shadow!
I hope this was helpful.
