java script to change field colors

Is there someone that can help me convert this java script code from CRM 4.0 to CRM 2011? The color is red.

              crmForm.all.new_manhourswk1.style.color = "#FFFFFF";

              crmForm.all.new_manhourswk1.style.backgroundColor = "#FF0000";

              crmForm.all.new_jobcompletewk1.style.color = "#FFFFFF";

              crmForm.all.new_jobcompletewk1.style.backgroundColor = "#FF0000";

              crmForm.all.new_jobcompletewk1.style.backgroundColor = "#FF0000";