Red(-ve)/Green(+ve) text for under/over monthly budget

Hello,

Newb to the forum.

I've devised a monthly savings sheet to allow me to track my savings towards a deposit on a house. My target is £xxx a month, but as I could contribute loose amounts of money I'd like to be able to display a field next to each month of how much over I've contributed or how much under I've contributed.

I'd like this to be represented as:-

If I contribute more than £xxx for a month then display it as green text and calculate how much over has been contributed.

If I contribute less than £xxx for a month then display it as red text and calculator how much under the contribution has been.

I'm really not sure how to do this, I would do it manually normally but surely there is a way of automatically representing it.

Look forward to your replies.

Mat