In this indicator the channel is built using three extreme points of ZigZag.

The indicator has two versions: with ZigZag indicator on a chart (ZigZag_NK_Channel2) and without (ZigZag_NK_Channel).

Input parameters:

//+----------------------------------------------+ 
//| Indicator input parameters                   |
//+----------------------------------------------+ 
input int ExtDepth=12;
input int ExtDeviation=5;
input int ExtBackstep =3;
//+----------------------------------------------+ 
//| Channel creation input parameters            |
//+----------------------------------------------+ 
input int FirstExtrNumb=1;                          // First peak index number (0,1,2,3...)
input color Upper_color=DeepSkyBlue;                // Upper channel line color
input ENUM_LINE_STYLE Upper_style=STYLE_SOLID;       // Upper channel line style
input ENUM_WIDTH Upper_width=w_3;                  // Upper channel line width
input color Middle_color=Teal;                     // Middle line color
input ENUM_LINE_STYLE Middle_style=STYLE_DASHDOTDOT; // Middle line style
input ENUM_WIDTH Middle_width=w_1;                 // Middle line width
input color Lower_color=Magenta;                   // Lower channel line color
input ENUM_LINE_STYLE Lower_style=STYLE_SOLID;      // Lower channel line style
input ENUM_WIDTH Lower_width=w_3;                 // Lower channel line width