coloring cells
 

I have 6 different conditions on my spreadsheet I want colored. I tried
conditional formatting but it didn't work for all of them. Columns c & d have
values. The conditions are if d-c <-20 = color d light green, -20 = green, <
20 = pink, 20 =red. Also, if any cell in column d is a blank i want it gray.
Then, if any amount in column d are -20, or 20 I want c to be colored
yellow. Is it possible?
C D
2 =gray
10 20 =pink
24 60 =red, cell c = yellow
50 45 =light green
75 10 =dark green, cell c = yellow