Picture from last summer of Pistol and his dam -
This is the two of them about Feb. 2010
In the above picture, do you notice the richness of Pistol's color versus his dam's? That is one indicator that he is not a sorrel, or red based, horse.
Now is this picture from last summer... Do you notice the "dirty" brownish color of his lower legs? That is one indicator of him being silver as they are pretty much that color all year long, fresh scrubbed or dirty in the pasture (you can see it in the above picture as well, and you can also see it in the pictures in my previous post). Now take a look at his eyes. Notice the white eye lashes? This is another indicator of silver.
Here is another picture of his legs -
Also, I know it is hard to see on these pictures of him, but he has striped hooves. Striped hooves is also another characteristic of silver.