google sheets – Change cell colors by day based on date in cell

I am new to Google Sheets and I need help with conditional formatting. I have column C, RESPA DATE, which has a date that varies for each borrower. I want to change the color of the cells in column D, INFORMATION SENT, daily within three days after column C until a date is entered in the cell. Once RESPA is triggered, I have three days to send information. I was wondering how I could format the cell to go green on Day 1, Yellow on Day 2 and Red on Day 3 until I grabbed a date and then it turns white again.