Change the color of a field in a Details view

Does anyone know how to change the color of a field in the Details view?  For example, I want to make a negative number Red and a positive number Green.  Thank you!!

Thanks so much!  I'm sure this is very rudimentary, but it looks like I need the view # and the field #.  

  1. I know how to get the view #; how do I get the field number? 
  2. I don't want it to blink on and off (if that's what you mean by "blink").  I just want the value to be colored red if the number is negative and green if it's positive.

Any help on those 2 would be fantastic.  Thank you!!