Why are the Basic and Advanced flatfield correction profiles greyed out?
The flatfield profiles are generated in Harmony, Columbus simply reports what profiles are available. If the "Basic" and "Advanced" FFC profiles are greyed out in the "Input Image" building block (or via the "Controls" panel in the Browse view) it is because the profiles were not generated by Harmony. You can check whether a correction was generated or not for a given measurement via the "Database Browser" in Harmony. You can filter by adding the keyword "Available Correction" for the measurement to indicate the best available correction method.
It’s worth noting that for Harmony datasets, Flatfield Correction is only possible if the dataset was exported from Harmony including the assay layout (See Harmony Help, section "Export Data"), or if the data was transferred to Columbus using the Columbus transfer functionality.