Here, we introduce OMCEC, a laboratory-based system that simultaneously measures the material composition, geometric properties, and motion of individual suspended aggregates in a non-invasive and non-destructive way. OMCEC consists of a full-color high-resolution optical system and real-time algorithms for material segmentation based on light spectra emission analysis, quantification of various geometrical properties, and motion detection with particle tracking velocimetry (PTV). We show applications of OMCEC for the composition analysis of aggregates made of biological matter and (i) mineral and (ii) microplastics.