$blend method
Implementation
@override
Color $blend(Color c1, Color c2, double blendWeight) {
if (c2.a == 0) return c1;
if (c1.a == 0) return c2;
// Calculate adjusted alpha for c2 based on blendWeight.
final alphaAdjustment = 2.0 * (blendWeight - 0.5);
final adjustedAlpha = (c2.a * 255.0 + alphaAdjustment * 255.0)
.clamp(0, 255)
.toInt();
final alphaBlend = adjustedAlpha / 255.0;
return Color.lerp(c1, c2, alphaBlend)!;
}