Traits

Name: Tobiano

Base Genotype: TO_

Skin Color:  Skin becomes pink under white markings. 

Eyes: If a white marking touches an eye, it becomes blue. Heterochromia is common. 

Description: Tobiano causes large round patches of white that cross over the top of the body. Round patches may have spotting within them (sometimes referred to as "cat tracks") and haloing around the edges. Tobiano may cause a high number of natural white markings on the face and legs. Flashy amounts of white on the legs is common. Facial markings should stay within a natural range on the forehead only, as tobiano does not cause large amounts of facial white like overo. Keep in mind that if a white patch turns the ears of the horse white, the horse is highly likely if not guaranteed to be deaf! Tobiano has several names for it's variations, which can all be searched on for real-life references: 

• "Skewbald" : a chestnut or bay horse with tobiano
• "Piebald" : a black horse with tobiano
• "Tovero" : a horse that has both tobiano and overo
• "Medicine Hat" : a tovero horse that is all white, except for a dark patch ("hat") over the ears, and dark patches on the chest and/or flank ("shields.") 

Design Guidance: At minimum, the horse may have natural white markings on the face, such as a snip, blaze, or stripe; and at least three legs with white markings that extend above the pastern. At maximum, the horse is nearly all white, with color only visible on the head. Ears are rarely turned white, but it happens (and may cause deafness). The mane and tail is white where it touches white patterned skin. Hooves become light colored where white patterns touch, as does skin. 

Examples of a chestnut tobiano, bay tobiano, and a black tovero (medicine hat) horse.