The mql4 language has a wide range of functionality for customizing the appearance of your charts. One of the most popular features of the language is the ability to change the color of a particular line on the chart. This is especially useful in Forex trading where different colors are typically used to represent different trends. With mql4, you can assign specific colors to specific lines, making it easier to identify trends and strategies. With mql4, you can use color to your advantage and make the most out of your trading strategies.