Use the <<Add Column Properties message:
:name << Add Column Properties(
Set Property(
"Event Handler",
Event Handler(
Click(JSL Quote(Function( {thisTable, thisColumn, iRow},
{},
n1rows = thisTable << Get Rows Where( :n1 == thisTable:thisColumn[iRow] );
n2rows = thisTable << Get Rows Where( :n2 == thisTable:thisColumn[iRow] );
thisTable << Select Columns( {thisColumn, :n1, :n2} ) << Clear Cell Colors;
thisColumn << Color Cells( {3, {iRow}} );
:n1 << Color Cells( {3, n1rows} );
:n2 << Color Cells( {3, n2rows} );
);
) )
)
)
)