Color coding cells from conditional statement

I am not great with conditional statements, but the goal is the following;

If K9 - N9 = 1 then make cell green

If K9 = N9 do nothing

If N9 - K9 = 1 then make cell red

Any help would be great

Here, try to follow the photo...

I put L9 but use N9 instead and adopt it for N9-K9...

For = no need for conditional formatting...

Great, thanks a lot. One more question...

Is it possible to hide the contents of a cell if it equals 0?

You can make by conditional formating same font color as cell color.
But it will be possible to see it when you select cell.

The Nameless: you can select a cell with the value zero in it and hit ctrl+1 to bring up the formatting window. From there select the number tab and click on "Custom" at the bottom. In the bar where it says "type:" enter 0;-0;;@

Will make the value of that cell blank if it equals 0