Conditional formatting based on a percentage difference

Hello

I wrote a question a few days ago but might not have been as clear as I could be. Apologies.

Using conditional formatting i am trying to write a formula that changes colour on the percentage difference of another cell.

An example would be if cell A1 contained a target of 5% in cell A2 would be an actual. If cell A2 is equal to A1 or better then it would be green. If cell A2 was within 10% less of A1 (i.e 4.5%-4.99%) then amber and red for the target minus 10% (i.e <4.49%)

I want to do this as a conditional formatting formula as the target figure will change but 10% difference will remain the same.

Hope someone can help

Thanks