Fabry-Pérot　structures　comprising　metal/interference　medium/metal　have　attracted　considerable　attention　as　lithography-free　and　scalable　color　reflectors,　as　such　structures　can　selectively　absorb　electromagnetic　waves　in　the　visible　range　to　produce　vivid　reflected　colors.　However,　traditional　methods　for　producing　high-saturation　reflected　colors　generally　use　a　narrow　full　width　at　half-maximum　(fwhm)　or　high　reflectivity.　This　work　proposes　a　nanoscale　multi-unit-stacking　structure　based　on　a　Ge2Sb2Te5　(GST)-ITO　interference　unit　to　obtain　high-saturation　colors　combined　with　fwhm　and　reflectivity.　Finite　element　simulations　and　experimental　measurements　reveal　that　the　additional　absorption　bands　introduced　by　the　stacking　interference　units　reduce　the　fwhm　of　the　peak　and　increase　reflectivity,　thus　improving　the　saturation.　Furthermore,　adjustments　in　the　number　of　stacking　cells　lead　to　changes　in　the　saturation　but　have　a　negligible　effect　on　the　hue.　The　use　of　germanium-antimony-tellurium　(also　denoted　as　GST)　as　a　phase-change　material　can　facilitate　further　adjustments　in　the　optical　tenability　of　the　structure　upon　phase　transition,　indicating　certain　potential　applications.　Moreover,　the　structure　exhibits　shortwave　infrared　shielding　owing　to　the　destructive　interference　of　the　GST　layer.　Additionally,　the　application　of　this　structure　in　color　printing　was　demonstrated.　This　study　simplifies　the　design　process　of　highly　saturated　colors,　circumvents　expensive　preparation　processes,　and　offers　the　possibility　of　shortwave　infrared　shielding.　The　nanoscale　structures　described　herein　indicate　new　opportunities　in　the　field　of　color　coatings,　intelligent　windows,　and　decorations.　©　2022　American　Chemical　Society.