Interracial unions were condemned as threats to French prestige and colonial authority.

Evidence

Despite these differences, their specific references to “decivilization” indicate why interracial unions in general were being condemned. These unions weakened French prestige by encouraging the administrator to “go native,” thus blurring the distinction between colonizer and colonized. Colonial administrators needed instead, they implied, companions of their own race and culture who would keep intact a specifically white French civilization. — Alice L. Conklin, A Mission to Civilize_ The Republican…, 593

Categorization

• ADDENDUM: Relevant to the moral-panics frame of ‘Complaints About Immodesty Go Way Back’ — colonial fears of racial mixing as a prestige/identity threat mirror sumptuary-era anxieties about dress signaling class.
• XREF: Connects to broader literature on hybridity anxiety and colonial boundary maintenance across empires.