Almost every breed has a certain set of characteristics. How tall they can be, acceptable colors and markings, how the animal is built, ect. Below is an outline of what most Thoroughbreds are like and what is acceptable.
Height:
somewhere around 16 hands
Color: any solid color; bay, chestnut, gray, roans,brown,and black are common.
Head: refined; widely-spaced, bold and intelligent eyes
Neck: longer and a little bit lighter than most breeds
Withers: well-defined and high
Back: smooth and evenly curved
Shoulder: long, sloping, deep and well-muscled
Heart Girth: relatively long and somewhat deep
Legs: clean and long with pronounced tendons. Cannonbone that should be relatively flat with the pastern. The pastern must be flexible and strong, and set at an angle slightly less than 45 degrees from the vertical. When viewed from behind or in front, the legs should be straight and move smoothly in unison through one plane.
