Set author name and comment colour in Keynote on Mac
You can specify the author name and colour that are used to identify your comments. Each person uses a different colour.
Set your author name
You can change the name that appears in the comments you make in Keynote. The new name appears the next time you comment in a presentation, as well as in comments you made previously.
Choose Keynote > Preferences (from the Keynote menu at the top of your screen).
Click General at the top of the preferences window.
Enter a name in the Author field, then close the preferences window.
The name doesn’t apply to presentations that are shared with others. For shared presentations, the name that appears in comments and in the participant list is the name you use with your Apple ID. To change it (without changing your Apple ID), open iCloud preferences (in System Preferences), click Account Details, click General, then type a name.
Important: If you change the name used with your Apple ID, the name appears in all apps and other locations that use your Apple ID.
If you stop sharing a presentation, the author name in comments reverts to the author name you set in Keynote preferences.
Change your author colour
Your author colour is associated with the comments you add to a presentation. You can change your author colour at any time.
Choose View > Comments > Author Colour (from the View menu at the top of your screen), then choose a colour.
If you have a presentation open, all your comments in the presentation switch to the new colour and any new presentations you create using the same author name use the new colour.
Note: You must add a comment or make a change using the new colour to save it in Keynote preferences. If you close the presentation without making any changes, the author colour reverts back to the previous colour.