Originally Posted by Quixotic
I'm not sure if you're looking for a particular pinto pattern or not, but just so you're aware, both Tobiano & Roan are mapped onto the KIT gene, meaning that if you breed to a Roan horse carrying the tobiano pattern, the resulting foal will inherit either roan or tobiano from that stallion, but not both.
It is possible to have both, it's just highly uncommon. If you breed a homozygous tobiano to a homozygous roan, you'll get both.
Do not breed your horse just to get some pretty colours. Do some google searching and find the foal you're looking for. It'll save you a lot of money and trouble and the world will have one less horse it didn't need.