You can find daylilies to go with almost every possible color scheme, from a deep burgundy or purple that is almost black through pale pastels. The only colors that daylilies don't come in are blue and pure white. And there are others that should be on the market soon that have faint lines almost like an etching near the throat of the flowers that look very blue indeed. Flower size varies by plant. Others have gigantic blooms - up to 7 inches across.
Daylilies also have a vast range of sizes.
And yes, it's true - some people have gardens filled with nothing but daylilies. And they are quite happy that way. The plant is easy to grow, bothered by very little in the way of pests and diseases and comes in such a spectacular array of colors and sizes that garden design is relatively simple. If you want to share, though, they don't mind division, and will soon fill right back out to their previous bountiful size. I have seen daylilies - like the orange ones at the roadside that never get fertilized and yet keep on growing and blooming.