Generally: the way to refer to "this" cell is to enter notation for the upper-left corner of the range being formatted. For example, if the range is C1:C, then C1 means "this cell".
For example, formatting C1:C with custom formula
=C1 < today() - 14
will format all cells in C with dates two weeks in the past.
If the range you want to format begins with row 8, and you think you may be inserting rows above that (thus shifting the range), then this formula can be used:
=and(C1 < today() - 14, row(C1) >= 8)
The formatting will apply only to rows starting with 8, but the range being the entire column, the formula will handle insertion of rows above row 8.
I forgot to update this yesterday but here is the final answer (thanks Irin Thirdwater!):
=(if(K3=if(F3=G3,1,if(F3=H3,2,if(F3=I3,3,10))),"ok","WRONG"))="ok"
=(if(K3=if(F3=G3,1,if(F3=H3,2,if(F3=I3,3,10))),"ok","WRONG"))="WRONG"
The first line with green highlight, second with red.
Hope this helps in case anyone else needs it!
Best Answer
The article you reference says that custom formulae only work in the new sheets. So, have you converted your file to the new Google Sheets? (https://support.google.com/drive/answer/3544847?hl=en&ref_topic=20322)