如果结束日期小于字段上的当前日期，如何将字段值更改为红色？

I want to change the field value as red color when end date is less than current date on field ? I have field name followup_date, If Follow up Date has passed then it should be marked as Red on Grid. The method will create previous date is less than current date, but i have no idea how to write this method? How is this possible? Can anyone help me out? Thanks in Advance...I want to change the field value as red color w