The Arabic Book of Routes and Realms (Kitāb al-Masālik wa-l- Mamālik) preserves the first maps we have from the Islamicate world. Created in the tenth century by al-Iṣṭakhrī (fl. tenth c.), the treatise described the Islamicate world from al-Andalus to Sindh. In addition to details about events, trade and customs, the treatise holds one world map and twenty regional maps that accompany the chapters about the twenty Islamicate regions. The contribution will analyse how colours enhanced the message of these maps. Moreover, the contribution will trace how the colours were modified during the book’s transmission. Surviving in sixty copies, the Book of Routes and Realms circulated between Istanbul and New Delhi until the late nineteenth century and was translated into Persian and Ottoman. Following the treatise through different collections, the contribution will show how Persian and Ottoman copies retained and changed al-Iṣṭakhrī’s maps (including their colours) in various contexts.