What you can do is add the \* CHARFORMAT switch to your REF fields and then format the field code in the desired color (but not using the Hyperlink style, which won't work, as you have seen). However, this will be time-consuming.

As Paul suggested, you could rethink this and use actual hyperlinks instead, assuming that you don't need the updated text of a cross-reference.

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Stefan Blom
Microsoft Word MVP

Microsoft 365 apps for business
Windows 11 Professional