No matter what you will have to clean it and in a shaded area that will have lots of moss issues and other staining from moisture that does not evaporate.

Maybe porous pave. It is permeable so there is less standing water than with concrete, and it does not have to be stained. It is pretty ugly though. It is also bouncy. Real stone, the "grout" (I know it is not really grout) has a tendency to crack. Manufactured stone has all the drawbacks of concrete plus the cracking grout of stone.

gravel?

A product like Trex will give you a wood look and is resistive of the elements. It can get slippery with frost, so be mindful of where you place it and the typical weather conditions around your house in the colder months.

Other natural woods like Ipe or Wenge are very weather resistant and have been used as decking materials in maritime climates. Natural woods will turn gray if you don't constantly reapply oil or stain, but it is personal preference if that is a concern to you.

Permeable pavers are another great alternative, and the aesthetic range has expanded over the last few years. If installed correctly, it should last a while. Downside would be if you are shoveling the area, the edges are more likely to catch the blade.

Stone and concrete both need to be sealed if weathering is a concern. Stone is more likely to spall, and some are worse than others. If you get a substantial paver stone, they should last a while. Shoveling can still be an issue with catching edges. Power washing these surfaces is just cleaning the dirt off, and does not extend their life. Concrete (when installed correctly) can be colored, stamped to look like stone, snow-melted, and although it will likely develop some cracking over its lifespan, it should last a long time.

In Colorado, the majority of our clients usually do stone pavers or concrete depending on their budget (concrete is cheaper in this area). Trex is used more than wood, but neither are very popular.

Hope that helps!

For outdoor flooring, why not use composite decking, It can with different colors, and it will have long life time.

It is said that there is a wood plastic composite flooring for outdoor in the flooring market, which is very popular because the material of this flooring is very environmentally friendly and will not harm the human body.

For outdoor deck’s flooring, people have always wondered which material to choose is the best.Some experts assert that the future plastic wood composite flooring will replace solid wood flooring, become a new trend in the flooring industry for outdoor. WPC outdoor flooring is mainly composed of wood (wood cellulose, plant cellulose) as the basic materials, thermoplastic polymer materials (PE plastics) and processing aids, etc. High-tech green and environment-friendly materials, which are made by heating and extruding with die equipment, have the properties and characteristics of wood and plastics. outdoor Plastic wood flooring is the best open-air flooring Now.