In the object explorer of SQL Server Management Studio (SSMS) SQL Source Control uses colored dots to indicate several different status types for the status of SQL Source Control or the type of change for an object.
The blue dot icon indicates that there is an uncommitted change in the database. Expand the database to see where the change is.
The white dot in the blue circle is a DROP (something that could cause a data loss issue i.e. something that may need a migration script).
The grey dot indicates that it needs to be refreshed i.e. if you have accidentally deleted a testing repository.
Which then turns into the blue a white swirl which indicates it's being checked for modification.
And no dots indicates there are no changes