“Moses married a black woman.”
You certainly cannot derive that from Biblical text.
Miriam and Aaron began to talk against Moses because of his Cushite wife, for he had married a Cushite.
The land of Cush is generally recognized as a Nubian land, and the Nubians are dark skinned people who we would refer to as black. This is contextually supported by the translators of the Septuagint who uniformly translate "Cush" into Αἰθιοπία (Aithiopia), the Greek name for Nubia.
Cushite = Nubian. These people are black.