Hey there

I'm really new to Excel and have been teaching myself as I go along but I've got stuck and no amount of Googling is helping.

I have 2 problems

1. I have put a formula in a cell which works out the days elapsed between 2 dates (unless the second date is blank, in which case it calculates to
today)
How do I make that highlight with a colour if the value is more than 14 working days?
So far I have =IF(F3>0, IF(H3>0,H3-F3, TODAY()-F3),0)

2. I have a cell (DG) which already has a drop down list in it (I used a bit of VBA programming I found on the net to make it so I can select multiples
from the list, don't know if that makes any difference). I need the cell to highlight with a colour if the date between cell AY and cell DG is more
than 90 days (TODAY) but I want it to stay blank if there is no date in AY. I also need it to turn back to normal (no fill) once I select something
from the list. Is that even possible?

Many Thanks
to put in there.