AfterAnimationColor

public IColorFormat AfterAnimationColor { get; set; }

[C#]
using (Presentation presentation = new Presentation("demo.pptx"))
{
    // Get the first effect of the first slide.
    IEffect firstSlideEffect = presentation.Slides[0].Timeline.MainSequence[0];
    
    // Change the effect After animation type to "Color"
    firstSlideEffect.AfterAnimationType = AfterAnimationType.Color;
    
    // Set the effect After animation color.
    firstSlideEffect.AfterAnimationColor.Color = Color.Green;
}