I think I got the palettes read

Services/FileParserService.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Collections;
 using System.IO;
 using System.IO.IsolatedStorage;
 using System.Linq;
@@ -31,8 +32,51 @@ namespace fxl.codes.kisekae.Services
             var header = Encoding.ASCII.GetBytes("KiSS");
             if (buffer[..header.Length].SequenceEqual(header))
             {
-                // Matching header I guess?
+                // Verify palette mark?
+                if (buffer[4] != 16) throw new InvalidDataException("File provided is not a valid palette file");
+                var colorDepth = Convert.ToInt32(buffer[5]);
+                var colorsPerGroup = BitConverter.ToInt16(buffer, 8);
+                var groups = BitConverter.ToInt16(buffer, 10);
+
+                palette.Colors = GetColors(new BitArray(buffer[32..]), colorDepth, colorsPerGroup, groups);
             }
+            else
+            {
+                palette.Colors = GetColors(new BitArray(buffer));
+            }
+        }
+
+        private Color[] GetColors(BitArray bitArray, int depth = 12, int colorsPerGroup = 16, int groups = 10)
+        {
+            _logger.LogTrace($"Converting bit array to colors");
+            var colorCounter = 0;
+            var colors = new Color[colorsPerGroup * groups];
+            var data = new bool[bitArray.Length];
+            bitArray.CopyTo(data, 0);
+
+            var length = depth / 3;
+            for (var index = 0; index < colorsPerGroup * groups; index += depth)
+            {
+                var greenStart = index + length;
+                var blueStart = index + length * 2;
+                
+                var red = GetValue(data[index..greenStart]);
+                var green = GetValue(data[greenStart..blueStart]);
+                var blue = GetValue(data[blueStart..(index + depth)]);
+                colors[colorCounter] = new Color(red, green, blue, colorCounter / colorsPerGroup, depth);
+                colorCounter++;
+            }
+
+            return colors;
+        }
+
+        private static int GetValue(bool[] data)
+        {
+            var bits = new BitArray(data);
+            var value = new int[1];
+            bits.CopyTo(value, 0);
+
+            return value[0];
         }
     }
 }