Abstract The organic–inorganic hybrid assembly composed of a dye molecule of large size, direct yellow ®50, as interleaved anionic molecule and layered double hydroxide host was investigated by X-ray diffraction. Upon hydrothermal post-synthesis treatment, the basal spacing is strongly decreased, explained by a drastic change in the orientation of the organic molecule against the LDH sheets, from perpendicular to parallel. The interactions were studied by 13C CPMAS NMR technique. Dispersed into polystyrene, the coloured filler was found to behave better in the viscoelastic domain than conventional surfactant LDH filler, maintaining similar rheological properties to filler-free PS. We demonstrate here that an intercalated nanocomposite polymer structure, providing an additional function as colour, is not preposterous.