withOpacity method Null safety

Color withOpacity(
  1. double opacity
)

Returns a new color that matches this color with the alpha channel replaced with the given opacity (which ranges from 0.0 to 1.0).

Out of range values will have unexpected effects.

Implementation

Color withOpacity(double opacity) {
  assert(opacity >= 0.0 && opacity <= 1.0);
  return withAlpha((255.0 * opacity).round());
}