Type‑based segmentation classifies coloured smart glass into electrochromic, thermochromic, photochromic, suspended‑particle‑device (SPD), and liquid‑crystal technologies, each with sub‑categories that affect cost and performance. Electrochromic glass, split into polymer‑based and inorganic oxide variants, dominates with the highest market share due to its reversible colour change, low power draw, and long cycle life. Thermochromic panels, differentiated by liquid crystal versus vanadium dioxide coatings, respond to temperature shifts and are favored in energy‑efficiency projects despite limited colour range. Photochromic glass, employing organic dyes or inorganic nanocrystals, offers passive light‑responsive tinting, primarily in automotive and architectural niches where simplicity outweighs active control. SPD glass utilizes micron‑scale particles suspended in a fluid matrix, delivering rapid, uniform dimming but at higher manufacturing complexity. Liquid‑crystal smart glass, with polarised layers, provides fast switching for privacy screens but requires constant power. The relative penetration of each type reflects functional requirements, cost constraints, and regulatory drivers across the market.