Conditional formatting dates

Hi
I am trying to format a date column on my spreadsheet and just can't see to get the formula right
Simplified, I have 2 columns, one with a deadline and one with a submission date. I want to made the deadline column red/amber/green if the deadline has passed today and the submission column is blank.
If there is a submission date then I need it to be red/amber/green for when it was submitted.
I have tried AND/IF/BLANK etc and just can't work it out.
Before submission I was thinking it needs to reference TODAY(), and after submission it'll be between the two columns?
It's been driving me insane all afternoon!!