Hiya! Wanted to know if having a horse with a rarer colouring makes them more valuable?? Thanks :)

That depends on what's causing the rarity. Is it because of some random colors like brindle or chimera? Then it doens't ad much to a horse's value as it can't be inherited. When chimera was introduced some people went crazy about it but that too has calmed down now. Is it because of inheritable patterns (like tobiano or splash white)? Are they heterozygous or homozygous? There are color breeders aiming for a specific colour or just horses with color rarity 1 of 1. For many it's important for their horses to have homozygous patterns as this way it's safe that the foals will inherit those patterns. Sole color horses usually don't go for much money (below 10 k).

If the horse has some good ratings (PEE+) than some patterns might increase the price.

Thankyou! :), how do I find out if my horse has a homozygous pattern, and what does a heterozygous pattern mean??

You can gene test a horse in the vet's office (find under "services"). In short some patterns, like tobiano, are expressed through a pair of allels - for tobiano it's "To" (dominant) and "to" (recessive). If the horse has at least one dominant allel it'll show the pattern. The pattern is called heterozygous if the horse just got one dominant allel: Toto. When bred it will pass on one of the two alleles to the foal so it could be the dominant or the recessive one. This way the foal could be tobiano or not. If the horse has two dominant alleles (ToTo) it will always pass on a dominant allel and the foal will definitely be tobiano.

Some players can tell by the horse's image if the horse has homozygous or heterozygous patterns (saves money). I think there is a guide about it somewhere in this section or under guides...