The DRAW_COLOR_ARROW drawing style plots the color arrows (symbols from Windings font).
The inidcator plots arrows on the chart, using the symbols from Windings font. Two indicator buffers are used: one for the price values, the other buffer contains the indexes of the colors. The code parameter is used to specify the base code: code=159 (circle).
The color, char size and shift are changed randomly after N=5 ticks. The initial properties of the plot1 graphic plot are defined using the #property preprocessor directive, further these properties changed randomly (see OnCalculate() function).
See also The Drawing Styles in MQL5