12 foot windsocks, aka wind indicators, are available in a range of colours.
12 foot standard duty windsocks are capable of functioning in winds up to 115 knots and is suitable most usual conditions. The standard weight windsock is slightly more active in very light wind conditions than the heavy duty one. 12 Foot Windsocks are the standard used at licensed and council airstrips and airports. The "Primary" windsock should be White and all others Yellow in colour. Some times there is more than one "Primary" Windsock at an airport, (one for each runway, and often one near the end of each runway).
White - Highly stable chemical and UV resistant. White is a very visible colour and has the least problem with fade.
Yellow - Highly stable chemical and UV resistant. Yellow can normally be seen the greatest distance, and tends to attract more than White. Yellow is easier to see against a background of sky, or as seen from the ground.