Thermocouples are color coded for easy identification. The color code gives us details as to the type of thermocouple, the temperature range, etc.
However, different countries have different color coding. Hence, it is better to check the thermocouple color coding protocol from the thermocouple manufacturer.
Below is a link to a Color Code Table for the Thermocouple
http://www.thermibel.be/documents/graphics/thermocouples/tc-color-complete.jpg