We developed a composite optical material composed of nanotubes and graphene nanoribbons (GNRs). We found that the macroscopic optical response of the composite is strongly governed by the specific combination of graphene nanoribbons and nanotube hosts, namely metallic and semiconducting single-walled carbon nanotubes (SWCNTs) and multi-walled boron nitride nanotubes (MWBNNTs). Selective synthesis of graphene nanoribbons was achieved using a bottom-up approach based on 4,4″-dibromo-p-terphenyl and 10,10′-dibromo-9,9′-bianthracene molecular precursors. Specifically, armchair graphene nanoribbons (AGNRs) with widths of 3, 6, 7, and 9 carbon atoms were synthesized on the surface and/or inside the nanotubes. The formation and structure of the GNRs were verified by Raman spectroscopy and high-resolution electron microscopy. The incorporation of AGNRs into nanotube films results in optical media with controllable absorption in the UV–visible spectral range. Moreover, a pronounced modification of the photoluminescence (PL) response of both carbon and boron nitride nanotube films was observed upon the formation of 3-AGNRs and 7-AGNRs within nanotubes. The 3-AGNRs exhibit different PL in carbon and boron nitride nanotubes due to PL quenching and energy transfer. Films and aqueous suspensions of GNRs@NTs show high stability over time as well as under intense ultrasonic treatment. These findings demonstrate that GNRs@NTs can serve as versatile platforms for printed and thin-film technologies in the development of active and passive components for optoelectronic devices.