Added hex color conversion (#1432)

* Added hex color conversion

---------

Co-authored-by: Frank Ray <52075808+FrankRay78@users.noreply.github.com>
Co-authored-by: Nils Andresen <nils@nils-andresen.de>

src/Spectre.Console/Color.cs

@@ -213,6 +213,50 @@ public partial struct Color : IEquatable<Color>
         return ColorTable.GetColor(number);
     }
 
+    /// <summary>
+    /// Creates a color from a hexadecimal string representation.
+    /// </summary>
+    /// <param name="hex">The hexadecimal string representation of the color.</param>
+    /// <returns>The color created from the hexadecimal string.</returns>
+    public static Color FromHex(string hex)
+    {
+        if (hex is null)
+        {
+            throw new ArgumentNullException(nameof(hex));
+        }
+
+        if (hex.StartsWith("#"))
+        {
+            hex = hex.Substring(1);
+        }
+
+        var r = byte.Parse(hex.Substring(0, 2), NumberStyles.HexNumber);
+        var g = byte.Parse(hex.Substring(2, 2), NumberStyles.HexNumber);
+        var b = byte.Parse(hex.Substring(4, 2), NumberStyles.HexNumber);
+
+        return new Color(r, g, b);
+    }
+
+    /// <summary>
+    /// Tries to convert a hexadecimal color code to a <see cref="Color"/> object.
+    /// </summary>
+    /// <param name="hex">The hexadecimal color code.</param>
+    /// <param name="color">When this method returns, contains the <see cref="Color"/> equivalent of the hexadecimal color code, if the conversion succeeded, or <see cref="Color.Default"/> if the conversion failed.</param>
+    /// <returns><c>true</c> if the conversion succeeded; otherwise, <c>false</c>.</returns>
+    public static bool TryFromHex(string hex, out Color color)
+    {
+        try
+        {
+            color = FromHex(hex);
+            return true;
+        }
+        catch
+        {
+            color = Color.Default;
+            return false;
+        }
+    }
+
     /// <summary>
     /// Converts a <see cref="ConsoleColor"/> to a <see cref="Color"/>.
     /// </summary>

src/Tests/Spectre.Console.Tests/Unit/ColorTests.cs

@@ -1,9 +1,73 @@
+using System.Drawing;
+
 namespace Spectre.Console.Tests.Unit;
 
 public sealed class ColorTests
 {
     public sealed class TheEqualsMethod
     {
+        [Theory]
+        [InlineData("800080")]
+        [InlineData("#800080")]
+        public void Should_Consider_Color_And_Color_From_Hex_Equal(string color)
+        {
+            // Given
+            var color1 = new Color(128, 0, 128);
+
+            // When
+            var color2 = Color.FromHex(color);
+
+            // Then
+            color2.ShouldBe(color1);
+        }
+
+        [Theory]
+        [InlineData("800080")]
+        [InlineData("#800080")]
+        public void Should_Consider_Color_And_Color_Try_From_Hex_Equal(string color)
+        {
+            // Given
+            var color1 = new Color(128, 0, 128);
+
+            // When
+            var result = Color.TryFromHex(color, out var color2);
+
+            // Then
+            result.ShouldBeTrue();
+            color2.ShouldBe(color1);
+        }
+
+        [Theory]
+        [InlineData(null)]
+        [InlineData("")]
+        [InlineData("#")]
+        [InlineData("#80")]
+        [InlineData("FOO")]
+        public void Should_Not_Parse_Non_Color_From_Hex(string noncolor)
+        {
+            // Given, When
+            var result = Record.Exception(() => Color.FromHex(noncolor));
+
+            // Then
+            result.ShouldBeAssignableTo<Exception>();
+        }
+
+        [Theory]
+        [InlineData(null)]
+        [InlineData("")]
+        [InlineData("#")]
+        [InlineData("#80")]
+        [InlineData("FOO")]
+        public void Should_Not_Parse_Non_Color_Try_From_Hex(string noncolor)
+        {
+            // Given, When
+            var result = Color.TryFromHex(noncolor, out var color);
+
+            // Then
+            result.ShouldBeFalse();
+            color.ShouldBe(Color.Default);
+        }
+
         [Fact]
         public void Should_Consider_Color_And_Non_Color_Equal()
         {