Here is a simple rework of your script. It works with your sample data, and should work with as many columns as you have in the data table
dt = Current Data Table();
// I changed the name from "col" to colNameList to keep from
// it being confused with the variable "Cols". It isn't
// confusing to JMP, just to me
colNameList = dt << get column names( string );
nc = N Items( colNameLIst );
// Loop across all columns
For( i = 1, i <= nc, i++,
// Create a variable that contains the "column" representation
// of the column name string value
Cols = Column( dt, i );
// If the column name starts with the string "Studentized Resid"
// and if so, then process
// I changed this because your Substr() function below indicates
// that the column with "Studentized Resid" will be at the beginning
If( Left( colNameList[i], 17 ) == "Studentized Resid",
// Find the minimum value for the column
MinValue = Col Min( Cols );
// Find all of the rows that have the minimum value. There
// could be more than one row with the minimum value, but this
// code only uses the first row
MinRows = dt << get rows where( As Column( Cols ) == MinValue );
// Theoretically, there should always be a matching value for this,
// but it is a good way to make sure the code will not fail. Also,
// if you ever want to deal with the posibility of more than one
// row matching the minimum, you would do it using this type of
// code structure
If( N Rows( MinRows ) > 0,
Cols << color cells( Yellow, MinRows )
);
// Output the requested values
Show( Substr( colNameList[i], 19 ), Cols[MinRows[1]] );
);
);
Jim