Parameters

tag

A user defined unique id used to reference the draw object. For example, if you pass in a value of "myTag", each time this tag is used, the same draw object is modified. If unique tags are used each time, a new draw object will be created each time.

bar

The bar the object will be drawn at. A value of 10 would be 10 bars ago.

y

The y value

color

The draw object color (reference)

// Paints a red down arrow on the current bar 1 tick above the high
DrawArrowDown("tag1", 0, High[0] + TickSize, Color.Red);

// Paints a blue down arrown on a three bar reversal pattern (see image below)
if (High[2] > High[3] && High[1] > High[2] && Close[0] < Open[0])
    DrawArrowDown(Time[0].ToString(), 0, High[0] + TickSize, Color.Blue);