In 1680, Texas would have been part of the Viceroyalty of New Spain, but I'm not sure it could be considered a "colony." For one thing, there were few, if any white settlers in the region, although settlement began in earnest in the area around what is now El Paso during the late seventeenth century.
AFAIK, when we refer to the colonies, we’re referring to the 13 colonies of England.