Console app that reads an image file and creates an excel file with each pixel colour info in the text and cell background (1 Pixel = 1 cell wide x 2 cells high)

ImgToXlsx.cs

using System;
using System.Collections.Generic;
using System.Drawing; // Nuget System.Drawing.Common
using System.Linq;
using IronXL; // Nuget IronXL.Excel

namespace ImgToXlsx
{
	class Program
	{
		static void Main(string[] args)
		{
			Console.WriteLine("Hello World!");

			WorkBook workbook = WorkBook.Create();
			WorkSheet sheet = workbook.CreateWorkSheet("image");

			Bitmap img = new Bitmap("Jace_37.png");
			sheet.InsertColumns(0, img.Width);
			sheet.InsertRows(0, img.Height * 2);
			for (int i = 0; i < img.Width; i++)
			{
				for (int j = 0; j < (img.Height * 2); j += 2)
				{
					Color pixel = img.GetPixel(i, j/2);

					var color = ClosestColor(pixel);

					var cell = sheet[GetRangeAddress(i, j) + ":" + GetRangeAddress(i, j + 1)];

					var hexColor = ColorTranslator.ToHtml(color);
					cell.Value = hexColor;
					cell.Style.BackgroundColor = hexColor;
					cell.Style.SetBackgroundColor(color);

					if (hexColor == "#20151B")
					{
						cell.Style.Font.Color = "#FFFFFF";
					}
				}
			}

			workbook.SaveAs("Result.xlsx");
		}

		static readonly string[] _columns = new[] { "A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z", "AA", "AB", "AC", "AD", "AE", "AF", "AG", "AH", "AI", "AJ", "AK", "AL", "AM", "AN", "AO", "AP", "AQ", "AR", "AS", "AT", "AU", "AV", "AW", "AX", "AY", "AZ", "BA", "BB", "BC", "BD", "BE", "BF", "BG", "BH" };
		static string GetRangeAddress(int x, int y)
		{
			return _columns[x] + (y + 1);
		}

		static readonly List<Color> _colors = new List<Color>
		{
			ColorTranslator.FromHtml("#FFFFFF"),//bg
			ColorTranslator.FromHtml("#D6AE98"),//face
			ColorTranslator.FromHtml("#20151B"),//shirt
			ColorTranslator.FromHtml("#352A30"),//beard/hair light
			ColorTranslator.FromHtml("#D0CCCC"),//teeth
			ColorTranslator.FromHtml("#5C4C4E"),//glasses
			ColorTranslator.FromHtml("#987070"),//mouth
		};

		static Color ClosestColor(Color a)
		{
			return _colors.OrderBy(c => ColorCloseness(c, a)).First();
		}


		static int ColorCloseness(Color a, Color b)
		{
			var rDist = Math.Abs(a.R - b.R);
			var gDist = Math.Abs(a.G - b.G);
			var bDist = Math.Abs(a.B - b.B);

			return rDist + gDist + bDist;
		}

	}
}