Ski slopes have a step gradation. Each track is classified depending on the complexity. Each difficulty level of the ski slope is marked by corresponding color. Most modern ski resorts use four color track classification system: green, blue, red and black.
Ski tracks are also divided on the quality of services. The first category includes serviced tracks, which are regularly compacted and leveled with special equipment. In the West such slopes are called groomed. The second category is patrolled tracks. These are tracks, which are regularly patrolled by security teams of the resort.
As for the track levels, here are presented general characteristics of each color:
Green slopes
It is the easiest difficulty track level, which is suitable for beginners and children. Most ski resorts in France, Poland and Spain build green slopes in the immediate vicinity of the residential area of the village. Often getting to such tracks does not require using the lift. Green tracks are the most sloping of all four levels. The angle of inclination for such routes generally does not exceed 25%.
Blue tracks
These tracks were prepared for those, who are already familiar with skiing, but not well enough to try the downhill. Blue tracks are the most popular in the world. They account for over half of all equipped ski slopes in the world. At most world resorts blue tracks are serviced by snow rackers. The maximum angle is the same as on the green slopes - 25%.
Red tracks
Red routes are designed for advanced skiers. Red tracks are popular among experienced skiers. These tracks differ from blue by steep hills, difficult tracks and long distances. The maximum angle of the red tracks is 40%, which in some cases does not allow using snow rackers. Almost on all red tracks work patrols.
Black tracks
Black tracks is the elite of alpine skiing. They are the most difficult tracks, which do not have a clear gradation. The black level of tracks means not only complexity. Some resorts mark with black color tracks with increased avalanche risks.
Orange and yellow trails
This is an additional classification for high complexity slopes, which are often off-piste. Yellow and orange tracks can be found at some ski resorts in Austria, Switzerland (Zermatt, Verbier), and Sweden.
It should be noted that the above mentioned parameters are only for recommendation. There is no common track classification system.
From one country to another the level of track complexity may vary depending on the reputation of the region. So, at the popular among professionals French ski resort of Val d'Isere blue track level will be similar to the red level in the Austrian Ellmau, which slopes are known as one of the best for beginners in Europe.
In addition, a number of countries use additional slope markers. Skiing in the U.S. and Canada: in these countries there is a separate category of double-black slopes, which are characterized as super-extreme. Moreover, at the ski resorts of New Zealand there are triple-black tracks, which local skiers call "suicide". Triple-black tracks can also be found at ski resorts in Norway and Sweden.