I have developed the logic I require, I just need some help in writing
the code to do it as I haven't used Excel for quite some time.

Basically, I need the code to perform the following:

Example:

If Y2 or AA2 0 and Z2 = 0, I need to change the colour of cell Z2 to
red.

I need to perform this function not only on row 2, but on rows 2 to
5642

Any help will be much appreciated.