Pre-multiply alpha channel when importing Unity textures

TextureAlphaPremultiplier.cs

using System;
using JetBrains.Annotations;
using UnityEditor;
using UnityEngine;

namespace UnityProject.Editor {

	public sealed class TextureAlphaPremultiplier : AssetPostprocessor {

		public void OnPreprocessTexture() {
			if (ShouldPremultiplyAlpha())
				((TextureImporter) assetImporter).alphaIsTransparency = false;
		}

		public void OnPostprocessTexture([NotNull] Texture2D texture) {
			if (!ShouldPremultiplyAlpha())
				return;
			
			int width = texture.width;
			int height = texture.height;
			for (int x = 0; x < width; ++x) {
				for (int y = 0; y < height; ++y) {
					Color color = texture.GetPixel(x, y);
					texture.SetPixel(x, y, Premultiply(color));
				}
			}

			texture.Apply();

			Debug.Log("Automatically premultiplied alpha for " + assetPath);
		}

		private static Color Premultiply(Color color) {
			float a = color.a;
			return new Color(color.r * a, color.g * a, color.b * a, a);
		}

		[Pure]
		private bool ShouldPremultiplyAlpha() {
			return assetPath.EndsWith(".png", StringComparison.OrdinalIgnoreCase);
		}

	}

}

Using Noesis?