how to change the type and color of lines in graph

[#1]

I am trying to show line of fit in graph builder for several sets of data. 

The data table have many columns, I want to show the column(i) vs column(1).

Every column can  be grouped by A1 & a, also can  be grouped by B1 & b, but except column(1).

The follow is the chart about column(2) vs column(1):

I use the follow script to change the type of lines:

Dispatch(
{},
"400",
ScaleBox,
{Legend Model(
8,
Properties( 2, {Line Color( -14948892 ), Line Style( "Dotted" )} ),
Properties( 3, {Line Color( -3636920 ), Line Style( "Dotted" )} )
)}
)

If the date column can  be grouped by A1 & a, also can  be grouped by B1 , b & bb, but except column(1).

Is there any way to draw the same graph without setting a particular line like :

Properties( 2, {Line Color( -14948892 ), Line Style( "Dotted" )} )