Calculated Column that allows user input if blank

Question

I need a list column with 6 choices, which are color categories: blue, red, green, grey, gold, purple. I want the column to default to a particular color based on another list column, called Project Type. It is my understanding the default value of a choice column cannot be based on another column. So instead, I've set up a calculated column with the following formula:

=IF(OR([Project Type]="A",[Project Type]="B",[Project Type]="C"),"Blue",IF(OR([Project Type]="D",[Project Type]="E",[Project Type]="F"),"Red",IF(OR([Project Type]="G"),"Green",IF(OR([Project Type]="H",[Project Type]="I"),"Grey",IF(OR([Project Type]="J",[Project Type]="K",[Project Type]="L",[Project Type]="M",[Project Type]="N"),"Gold","")))))

The problem is, there are other project types (project types O through Z, let's say) that do not default to a specific color category, but rather require a user to choose one manually. When the IF statement defaults to ELSE and leaves the column blank, I need the user to be able to either choose or input a color to fill in those blanks, but unfortunately, calculated column fields seem to be read only. Is there any workaround to allow manual input in a calculated column when the calculation leaves it blank? Or some other solution I'm not seeing?

Answer 1

No, you cannot allow manual input for a calculated colum in SharePoint list.

For your requirements you have to customize the list form using Power Apps.

You can use similar formula like above calculated formula for "DisplayMode" property of choice (dropdown) control in Power Apps.

If Project type is from A to N, display mode will be "Disabled" with default value else you can set display mode to "Edit" so that user can manually select the option.