Here is a tough question! IF formula output

I am putting together a spreadsheet and I am pretty handy with Excel but ran into a problem and I would greatly appreciate any help.

What I am trying to do is use an if formula, for example =IF(c3=d3,A,F), but instead of having the output if the value is true be A and the output if the value is false be F, I would like the value to be a solid green box if true and a solid red box if false......

Anyone know how to do this?!?

Thank you.

thanks, i think i have something working here!

You don't really need a formula in the cell at all, which might be useful if you want any value in it. Assuming the cell you want to colour is E3

Select E3
Use ordinary formatting to colour cell red

Then use conditional formatting with "formula is" option and formula

=C3=D3

select green pattern

OK

Of course both my suggestion and VBA Noob's will give you a green cell if both C3 and D3 are blank. You can prevent that if you want by altering formula to

=(C3=D3)*(D3<>"")