Creates a texture where each mip level is a different color.

MakeWeirdMips.cs

public class MakeWeirdMips : MonoBehaviour
{
    [MenuItem("Pema/MakeWeirdMips")]
    public static void MakeWeirdMipsAsset()
    {
        Texture2D tex = new Texture2D(1024, 1024, GraphicsFormat.R32G32B32A32_SFloat, TextureCreationFlags.MipChain);
        FillMip(tex, Color.magenta, 0); // 1024
        FillMip(tex, Color.green, 1); // 512
        FillMip(tex, Color.blue, 2); // 256
        FillMip(tex, Color.red, 3); // 128
        FillMip(tex, Color.green, 4); // 64
        FillMip(tex, Color.blue, 5); // 32
        FillMip(tex, Color.red, 6); // 16
        FillMip(tex, Color.green, 7); // 8
        FillMip(tex, Color.blue, 8); // 4
        FillMip(tex, Color.red, 9); // 2
        FillMip(tex, Color.magenta, 10); // 1
        AssetDatabase.CreateAsset(tex, "Assets/WeirdMips.asset");
        var material = AssetDatabase.LoadAssetAtPath<Material>("Assets/WeirdMips.mat");
        material.mainTexture = tex;
    }

    public static void FillMip(Texture2D tex, Color color, int mipLevel)
    {
        var size = tex.width >> mipLevel;
        var arr = new Color[size * size];
        Array.Fill(arr, color);
        tex.SetPixels(arr, mipLevel);
    }
}