One way:

Select the third and fourth column (say, C:D, with C1 active). Choose
Format/Conditional Formatting:

CF1: Formula is =COUNTA(E1:F1)<2
Format1: <patterns/<red

In article ,
amrezzat wrote:

heloo
suppose that i have 6 coloumns as follw

1 2 3 4 5 6

i want to change the font color of the third and forth column to red
when the fifth and sixth column is not blank