The most common color is red, but the plants come in every shade of red, orange, yellow and white, even in bicolor forms. They are native to the mountains of Papua New Guinea, but many of the colors are the result of hybridizing and selective breeding. Some of these are also easier to grow.
This is a pale yellow form that is referred to as semi-alba. My plant is in bloom almost year around and continues to produce new flowers as the old ones fade. The plant itself is 2 cm tall, and the flowers are 3 cm long. I grow it cool and mounted and give it as much light as I can.