During aging-associated inflammation, microglia adopt chronic overactivity of their pro-inflammatory response that increases risk of neurodegenerative. Aging microglia also accumulate ROS-producing autofluorescent lipofuscin. Identifying aging-related changes in the spectral profile of this autofluorescent brain lipofuscin will help to develop autofluorescent-based biomarkers. Here we hypothesized that aging increases microglia autofluorescence and elicits a distinct spectral signature from young brain autofluorescence. To detect changes in the microglial autofluorescence signal with aging, we used young (3 months) and aged (21 months) female C57BL/6 mice. Brain microglia were immunolabelled for ionized calcium-binding adapter molecule 1 (Iba-1) with Alexa Fluor 647. We assessed microglial autofluorescence granules in the hippocampus. Emission spectra of granules from young and aged unstained brain tissue were analysed using a confocal microspectroscopy Using Bitplane Imaris software, we established that aging significantly increased the total volume of autofluorescence in hippocampal microglia, with significantly higher number of large (> 10 μm³) granules in the aged. Spectral signatures show that both ages displayed a broad emission band with peaks between 510 nm and 675 nm, eight of which were common for both ages. When signatures were examined separately according to size, larger aggregates in aged brains were more intense in far-red peaks compared to smaller aggregates from both the aged and young, causing a spectral redshift. Our findings suggest that autofluorescent material aggregates with age in microglia and may be an autofluorescent biomarker of inflammaging. These findings highlight an opportunity for future spectral identification of aging-related autofluorescent signals of microglia during brain inflammaging.