Try this.
In cell B2 go to conditional formatting and set conditions as
1. Formula is =(B2="")
Set Pattern as "no colour", font as "automatic"
2. Formula is =(B2=TODAY()-365)
Set Pattern as Red
3.Formula is =(B2=TODAY()-275)
Set Pattern as amber
Once CF is finished click OK and return to cell B2.
Right click and copy
Then highlight all the cells you wish the CF format to be used in
Right click and go Paste Special/Format
That does the trick on my test sheet.
The only thing to occur though is that one day after the CF is triggered the cell will no longer be coloured amber in the first instance ,
What action do you propose to do once cell turns amber?
Pedro