Structural color, which generates vivid colors via the geometrical arrangement of resonant nanostructures, can enhance the recyclability and mechanical stability of colors; structural colors have been intensively studied in recent years, owing to their high resolution, color purity, and stability compared to colors generated by dyes and pigments. Dielectric materials, which possess a suitably high refractive index and low loss in the visible range, are ideal materials for structural colors. However, the static optical performances of most structural colors impose restrictions on their applicability. This article reviews the fundamental physics of dielectric structural color procedures based on Mie resonance; furthermore, it highlights recent progress in tunable structural colors, focusing on their operation mechanisms and practical applications, including the geometric parameters of the nanostructures, optical parameters of the building materials and environments, and properties of the optical stimuli. This article is concluded by presenting an outlook on the future potential of structural colors, as well as the challenges that remain to be addressed.