This ProBuilder code snippet demonstrates how to visually represent buy and sell zones on a trading chart by filling areas between the closing price and the SAR (Stop and Reverse) indicator using colored triangles. The color fill changes based on whether the closing price is above (buy zone) or below (sell zone) the SAR indicator.

indicator1 = SAR[0.02,0.02,0.2]
achat = close > indicator1
If achat then
    drawtriangle(barindex[1], close[1], barindex, indicator1, barindex[0], close[0]) coloured(0,100,0,25) bordercolor(0,100,0,0)
    drawtriangle(barindex, indicator1, barindex[1], indicator1[1], barindex[1], close[1]) coloured(0,100,0,25) bordercolor(0,100,0,0)
else
    drawtriangle(barindex[1], close[1], barindex, indicator1, barindex[0], close[0]) coloured(100,0,0,25) bordercolor(0,100,0,0)
    drawtriangle(barindex, indicator1, barindex[1], indicator1[1], barindex[1], close[1]) coloured(100,0,0,25) bordercolor(0,100,0,0)
Endif
return

Explanation of the Code:

• Indicator Setup: The SAR indicator is initialized with specific parameters (acceleration factor start, increment, and maximum).
• Condition Check: A boolean variable achat is used to check if the closing price is greater than the SAR indicator value, indicating a potential buy signal.
• Drawing Triangles for Buy Zone: If the condition is true (buy zone), two green semi-transparent triangles are drawn between the previous and current bars to visually represent the area above the SAR indicator.
• Drawing Triangles for Sell Zone: If the condition is false (sell zone), two red semi-transparent triangles are drawn in a similar manner but below the SAR indicator to represent the sell zone.
• Color and Border Settings: The coloured function is used to set the fill color of the triangles, and the bordercolor function is used to set their border color, enhancing visual clarity.

This visual representation helps traders quickly identify potential buy or sell zones based on the position of the closing price relative to the SAR indicator.