We present colour dataset from the lowermost Pliensbachian organic-rich hemipelagic Santiurde section (Basque-Cantabrian basin, north Iberian palaeomargin, Spain). The Santiurde section studied herein is exposed at exit 144 of motorway A67 (UTM X411431.091 Y4769002.593), approximately 50 km south-west of Santander city. The 22.5 m-thick succession is characterized by an alternation of limy and marl/shale beds. In order to determine if sedimentation was orbitally forced, a cyclostratigraphic analysis of the hemipelagic rythmites was undertaken. To this end, a total of 373 hand samples were collected and analysed for magnetic susceptibility and rock powder colour. Sampling was mainly carried out in 2019. Rock-powder samples were scanned in a dark room using a desktop office scanner in order to obtain the average colour (RGB value) value using the ImageJ software.