var diffBuilder = new InlineDiffBuilder(new Differ());
var diff = diffBuilder.BuildDiffModel(before, after);

foreach (var line in diff.Lines)
{
    switch (line.Type)
    {
        case ChangeType.Inserted:
            Console.ForegroundColor = ConsoleColor.Red;
            Console.Write("+ ");
            break;
        case ChangeType.Deleted:
            Console.ForegroundColor = ConsoleColor.Green;
            Console.Write("- ");
            break;
        default:
            Console.ForegroundColor = ConsoleColor.White;
            Console.Write("  ");
            break;
    }

    Console.WriteLine(line.Text);
}

/// <summary>
/// Provides methods for generate differences between texts
/// </summary>
public interface IDiffer
{
    /// <summary>
    /// Create a diff by comparing text line by line
    /// </summary>
    /// <param name="oldText">The old text.</param>
    /// <param name="newText">The new text.</param>
    /// <param name="ignoreWhiteSpace">if set to <c>true</c> will ignore white space when determining if lines are the same.</param>
    /// <returns>A DiffResult object which details the differences</returns>
    DiffResult CreateLineDiffs(string oldText, string newText, bool ignoreWhiteSpace);

    /// <summary>
    /// Create a diff by comparing text character by character
    /// </summary>
    /// <param name="oldText">The old text.</param>
    /// <param name="newText">The new text.</param>
    /// <param name="ignoreWhitespace">if set to <c>true</c> will treat all whitespace characters are empty strings.</param>
    /// <returns>A DiffResult object which details the differences</returns>
    DiffResult CreateCharacterDiffs(string oldText, string newText, bool ignoreWhitespace);

    /// <summary>
    /// Create a diff by comparing text word by word
    /// </summary>
    /// <param name="oldText">The old text.</param>
    /// <param name="newText">The new text.</param>
    /// <param name="ignoreWhitespace">if set to <c>true</c> will ignore white space when determining if words are the same.</param>
    /// <param name="separators">The list of characters which define word separators.</param>
    /// <returns>A DiffResult object which details the differences</returns>
    DiffResult CreateWordDiffs(string oldText, string newText, bool ignoreWhitespace, char[] separators);

    /// <summary>
    /// Create a diff by comparing text in chunks determined by the supplied chunker function.
    /// </summary>
    /// <param name="oldText">The old text.</param>
    /// <param name="newText">The new text.</param>
    /// <param name="ignoreWhiteSpace">if set to <c>true</c> will ignore white space when determining if chunks are the same.</param>
    /// <param name="chunker">A function that will break the text into chunks.</param>
    /// <returns>A DiffResult object which details the differences</returns>
    DiffResult CreateCustomDiffs(string oldText, string newText, bool ignoreWhiteSpace, Func<string, string[]> chunker);
}

/// <summary>
/// Provides methods that generate differences between texts for displaying in a side by side view.
/// </summary>
public interface ISideBySideDiffBuilder
{
    /// <summary>
    /// Builds a diff model for  displaying diffs in a side by side view
    /// </summary>
    /// <param name="oldText">The old text.</param>
    /// <param name="newText">The new text.</param>
    /// <returns>The side by side diff model</returns>
    SideBySideDiffModel BuildDiffModel(string oldText, string newText);
}