add ability to specify RGB colors as names from the X11 rgb name list

src/config/Config.zig

@@ -20,6 +20,7 @@ const Key = @import("key.zig").Key;
 const KeyValue = @import("key.zig").Value;
 const ErrorList = @import("ErrorList.zig");
 const MetricModifier = fontpkg.face.Metrics.Modifier;
+const RGBName = @import("rgb_names").RGBName;
 
 const log = std.log.scoped(.config);
 
@@ -2139,7 +2140,12 @@ pub const Color = packed struct(u24) {
     }
 
     pub fn parseCLI(input: ?[]const u8) !Color {
-        return fromHex(input orelse return error.ValueRequired);
+        if (input == null) return error.ValueRequred;
+        if (RGBName.fromString(input.?)) |name| {
+            const rgb = name.toRGB();
+            return Color{ .r = rgb.r, .g = rgb.g, .b = rgb.b };
+        }
+        return fromHex(input.?);
     }
 
     /// Deep copy of the struct. Required by Config.
@@ -2188,6 +2194,10 @@ pub const Color = packed struct(u24) {
         try testing.expectEqual(Color{ .r = 10, .g = 11, .b = 12 }, try Color.fromHex("0A0B0C"));
         try testing.expectEqual(Color{ .r = 255, .g = 255, .b = 255 }, try Color.fromHex("FFFFFF"));
     }
+
+    test "fromName" {
+        try std.testing.expectEqual(Color{ .r = 0, .g = 0, .b = 0 }, try Color.parseCLI("black"));
+    }
 };
 
 /// Palette is the 256 color palette for 256-color mode. This is still