If you want to customize how track changes markup appears in your documents, the Advanced Track Changes Options dialog gives you control over every aspect of markup appearance.
To open the Advanced Track Changes Options dialog:
From the Review tab, in the Tracking group, click the Change Tracking Options dialog box launcher.
In the Track Changes Options dialog, click Advanced Options.
To change the formatting of a particular type of markup, choose an option from the drop-down menu next to the type of markup you want to change.
By default, Word assigns a different color for each reviewer’s insertions, deletions, and formatting changes.
Note: Assigned colors may change when the document is closed and reopened or when someone opens it on another computer.
You can’t choose which color Word assigns to reviewers, but you can choose colors for different types of markup. If you prefer to have colors determined by the type of markup, instead of by author, select a color from the drop-down menu: