Goldfish should only be housed with goldfish. There are many interesting breeds of goldfish and they come in every color under the sun!
A general rule is single tailed goldfish with other singled tailed fish but fantails, ryukins or wakin can also be housed with single tailed fish. The reason is singled tailed fish are faster and more aggressive when it comes to eating.
You can keep fantails, ryukins, orandas, lionheads, and ranchus together as well
Telescope eyed fish should be kept with other telescopes, celetials, and bubble eyes. They have extremly poor vision and are slow swimmers so it is diffucult for them to compete for food.
All these types come in red, red and white, red an black, blue, green, lavender, chocolate, tri-color, matt, and calico. Telescopes, orandas and now ryukins can be found in black and white but you'll pay the price for them, if you can find them. Goldfish are so unique and facinating to collect.