Declarations of variables within the SQL statement are allowed, prefixed with a ":" sign or without. If variables are recognized, they will be highlighted in red after executing the Format function.
Note: If table names are in red it indicates that the table and corresponding columns are not recognized. Check these things:
Is there sufficient privileges under the login user to access the table
Are you connected to the correct database and schema
Execute the Synchronize Data Dictionary function to make sure you have the most up-to-date database information in memory.