User Configuration > Administrative Templates > Microsoft Office 2016 > Shared paths
User
HKCU\software\policies\microsoft\office\16.0\common\general
This policy setting allows you to specify a common location for sharing custom Office themes with users in your organization. A theme contains the following design elements: - Fonts - Colors - Effects If you enable this policy, the Themes gallery will list any custom themes that are found in the location that you specify. Only one location is allowed for this policy setting. Logical and UNC paths are supported. If you disable or don’t configure this policy, the Themes gallery will not list any custom themes, unless the user has saved one for their personal use.