During the First World War, Britain and France mobilized colonial soldiers and non-European civilian laborers on an unprecedented scale to support military operations on the Western Front. The massive deployment of soldiers and contract workers from Africa, Asia and the Caribbean temporarily transformed the racial demographics in Western Europe and ruptured the geographic and social boundaries between European metropoles and their overseas colonial territories. Framing the Western Front as a sociocultural contact zone, this article examines how colonial soldiers from the British West Indies Regiment (BWIR) navigated interracial and inter-imperial encounters in wartime France. The article illustrates how BWIR soldiers’ intimate exchanges across the color line—whether at military work sites, in places of leisure or in private homes—provided an opportunity to compare British and French racial policies and to assess the status of colonials of color in the British Empire.