(I unchecked the bubble for your lines so you could see it better, although I could add you so you could 'color' it, but then you could check your lines so you can see the difference.)Dark Blue: A well conformationed horse should have a somewhat triangular head, although the angles shouldn't be sharp.
Lime Green: Thats where some shading would go. The line on the shoulder is the point or slope of shoulder. That is the line on which your breastcollar would fit. The longer the shoulder the more reach the horse has.
Dark Brown: Horses should also have a somewhat triangluar neck.
Tan: You want a prominant wither, that extends well into the back. (BTW: drawing full horses: you want the topline to be shorter than the underline, and you want the deepest part to be the heart girth.)
Yellow and Teal: The underlength of the horses neck (yellow) should be approximately the length of the horses head (teal). Although the neck should look proportinate to the head.
