Here is a picture of both Spirit and Rain. Diffrent people think diffrent things on the the breeds of these horses. I'm going to tell you what I think and so mabe it could open up a few more possiblities or elimanate some old ideas.

I'll start with Spirit to me there is no question of Spirit's breed.I think he is a kiger mustang. Here is why :

Mustangs are found in all colors, including black, bay, dun, palomino, gray and spotted.Kiger Mustangs are primarily dun in color and have primitive markings, including zebra-like stripes on the upper legs and shoulders as well as stripe running down the middle of the back into the tail—this is called a dorsal stripe.Though they do not have to have all of these markings.I beleive that spirit has  a dorsal stripe. Typically a dun horse is a shade of muted tan or a light brown-gray with dark brown or black manes.  A dun colored horse may have many, but not all, of the primitive markings which include the dorsal stripe, two-toned manes and/or tails, zebra-like stripes on the upper legs and shoulders, dark color around muzzle and ears with dark outlines and lighter interiors.Kiger Mustangs, as a rule, are agile and intelligent, with  stamina and surefootedness.Example of a Dun Kiger mustang (pic.1) and sevreal more mustang (pic.2) picture 3 is a picture of spirit.

Now lets go to Rain.

Let's cut right to the point here.

Here are some possible canadiates.

The horse to the left looks like Rain the right horse being a leapord spotted Appaloosa the left being of the pinto coat.On other sites ive herard of Rain being an appaloosa picture 2 or a gray picture 1.

Although I don't think either one of these resemble rain in any way.

 however many breeds of horse carry pinto patterns.(that consists of large patches of white and any other color)Pinto patterns are visually and genetically distinct from the leopard complex spotting patterns characteristic of horses such as the Appaloosa(picture 1)

Ive heard of her being a Skewbald also.

Skewbald:  Any pinto pattern on any base coat other than black. As chestnut and bay are the most common base coat colors, skewbalds are most often chestnut and white or bay and white. At one time, the term may have applied more specifically to brown-looking pinto horses, but today it encompasses any color other than black.

 

Here are some reasons ive heard of people thinking of Rain as a Appaloosa.

Most representatives have colorful spotted coat patterns, striped hooves, mottled skin and white sclera around the eye.The "foundation" or "working Appaloosa is still sometimes seen, especially on working ranches. This is a slightly smaller, leaner animal There are also some Appaloosas that display more of a Thoroughbred or sport horse conformation – taller, with longer legs and a leaner buildHowever, it is the unique spotting pattern that most people associate with the Appaloosa horse. These spotted markings are not the same as the "dapples" sometimes seen in grays and some other horse colors. Appaloosa markings overlay the base coat color, and have several pattern variations.

Gray or grey is a coat color of horses characterized by progressive silvering of the colored hairs of the coat.[1] Most gray horses have black skin and dark eyes; unlike many depigmentation genes, gray does not affect skin or eye color

 Their adult hair coat is white, dappled, or white intermingled with hairs of other colors.

Well I think that Spirit is a Dun Kiger mustang. Rain is harder to figure out since there are many breeds that include the pinto coat but i've tried to make people releize that the chance she is a gray or Appaloosa are slim since none of these look anything like her in any of their varities.

This is my first article hope you enjoyed!!!:)