In WebStorm each file has its own status marked with a specific color. The file status denotes correspondence of the actual file content with the one marked as 'current'.
In the editor, each line in a file is checked whether it corresponds to the state at the 'current' point and marked with a specific color at the left gutter area.
You can customize the default colors:
In this section:
File status in views
|Black||Up to date||File is unchanged.
|Gray||Deleted||File is scheduled for deletion from the repository.
|Blue||Modified||File has changed since the last synchronization.
|Green||Added||File is scheduled for addition to the repository.
|Violet||Merged||File is merged by your VCS as a result of an update.
|Brown||Unknown||File exists locally, but is not in the repository, and is not scheduled for adding.
|Olive||Ignored||File will be ignored in any VCS operation.
|Light brown||Hijacked||File is modified without checkout. This status is valid for the files under Perforce, ClearCase and VSS.
|Red||Merged with conflicts||During the last update, file was merged with conflicts.
|Lilac||Externally deleted||File is deleted locally, but was not scheduled for deletion, and still exists in the CVS
|Dark cyan||Switched||The file is taken from a different branch than the whole project. This status is valid for CVS and
Line status in the editor
|Modified||Denotes the lines modified since the last synchronization.|
|Added||Denotes the lines added since the last synchronization.|
|Deleted||Denotes the lines removed since the last synchronization.|