IF ELSE in Java Script

for some reason the following code is not coloring as should. What did I do wrong?

        if (Group == 'Customer') {
            if (Status != 'Agreement')
                cell.css('color','blue');
        }
        else
        if (Group == 'Non-customer') {
            if (Status == null)
                cell.css('color','green');
            else
            if (Status != 'Agreement')
                cell.css('color','yellow');

            else
            if (Status == 'Not declared')
                cell.css('color','purple');
        }