Which two colors alternate on the gates in a standard alpine slalom course?

Standard alpine slalom courses alternate red and blue gates.

The alternating colors help racers and officials distinguish successive gate lines as the course zigzags down the slope. A racer must pass each gate correctly, usually with both ski tips and both feet passing around the outside of the turning pole or gate line.

Slalom gates are closely spaced compared with giant-slalom gates, so competitors make rapid, short-radius turns. Skiers commonly use protective guards on their hands, arms, shins and face to strike or brush aside the poles while keeping their racing line.

The colors do not indicate separate difficulty levels or different scoring values. They are visual course markers. In parallel events, racers may use different lane colors, but red and blue remain the familiar pairing in standard alpine slalom course design.