Conditional formatiing

I am trying to format a report where I have 3 conditions where I want the font to be red otherwise black

Using =IIF(Fields!Primary_Diagnosis.Value = "428.0 CHF NOS","Red","Black")

I tried adding "486 pneumonia organism nos" and  "410.91 ami nos"

using the same logic and was not able to change the font to red.

Any suggestion would be greatly appreciated

Thank you in advance