For a while now you have been able to create local custom fields in Project for the web: https://pwmather.wordpress.com/2020/09/04/task-level-custom-fields-support-in-projectfortheweb-workmanagement-taskmanagement-msproject-office365-ppm/ but this didn’t include Choice field types where users can select values from a list. A recent update to the service has now enabled Choice fields:
Now you can consistently tag the tasks with a value from the custom Choice field. To create a new Choice field click the + Add column option then + New field:
This will load the New Field dialog:
Change the Type to Choice:
Give the field a name and add the choice values. There are three inputs by default but click the Add a Choice option to an another choice value. In my example Choice field I have created a Status RAG field:
Tip: To add the icon, press the Windows + . key:
I can now set the choice value against my tasks as seen below:
A great addition to the local custom fields in Project for the web!
Modern Work Management - Project and the Power Platform blog 