Case Statement for Data Limiter Expression Error

[Daniel Ramirez 2]

I am trying to run this case statement in Spotfire Limit Data Using Expression and getting errors."Incorrect Expression type string. The expression must have type "Boolean"."

Not exactly sure what is wrong and tried messing around with it with no success. Trying to filter out the data

 

case when (([TypeDesc] is not null) and ([TypeDesc]~='Red')) or (([Coating] is not null)

and (([Coating]~='Blue') or ([Coating]~="Red"))) then 'Red; ' else null end

[Michael Kalada 2]

have you tried as not equal to instead of ~=