Material Design 3 uses a new color system called HCT (hue, chroma, tone). HCT is a new color system that perceptually accurate developed by Google for design. The color system that mostly used by designers today is HSL, but HSL (hue, saturation, lightness) isn’t remotely accurate, it doesn't ensure appropriate color contrast, accessibility standards, and consistent lightness/colorfulness across hues.
material_color_utilities package implements HCT, and can be used as a dependency. Flutter sdk currently depends on material_color_utilities, so it is not an additional dependency to projects. (flutter sdk pubspec.yaml)
Article from Material Design Blog
Material Design 3 uses a new color system called HCT (hue, chroma, tone). HCT is a new color system that perceptually accurate developed by Google for design. The color system that mostly used by designers today is HSL, but HSL (hue, saturation, lightness) isn’t remotely accurate, it doesn't ensure appropriate color contrast, accessibility standards, and consistent lightness/colorfulness across hues.
material_color_utilities package implements HCT, and can be used as a dependency. Flutter sdk currently depends on material_color_utilities, so it is not an additional dependency to projects. (flutter sdk pubspec.yaml)