diff --git a/common/rfb/PixelFormat.cxx b/common/rfb/PixelFormat.cxx
index 769afc6..8a4e71c 100644
--- a/common/rfb/PixelFormat.cxx
+++ b/common/rfb/PixelFormat.cxx
@@ -132,55 +132,6 @@
 }
 
 
-Pixel PixelFormat::pixelFromRGB(rdr::U16 red, rdr::U16 green, rdr::U16 blue,
-                                ColourMap* cm) const
-{
-  if (trueColour) {
-    rdr::U32 r = ((rdr::U32)red   * redMax   + 32767) / 65535;
-    rdr::U32 g = ((rdr::U32)green * greenMax + 32767) / 65535;
-    rdr::U32 b = ((rdr::U32)blue  * blueMax  + 32767) / 65535;
-
-    return (r << redShift) | (g << greenShift) | (b << blueShift);
-  } else if (cm) {
-    // Try to find the closest pixel by Cartesian distance
-    int colours = 1 << depth;
-    int diff = 256 * 256 * 4;
-    int col = 0;
-    for (int i=0; i<colours; i++) {
-      int r, g, b;
-      cm->lookup(i, &r, &g, &b);
-      int rd = (r-red) >> 8;
-      int gd = (g-green) >> 8;
-      int bd = (b-blue) >> 8;
-      int d = rd*rd + gd*gd + bd*bd;
-      if (d < diff) {
-        col = i;
-        diff = d;
-      }
-    }
-    return col;
-  }
-  // XXX just return 0 for colour map?
-  return 0;
-}
-
-
-Pixel PixelFormat::pixelFromRGB(rdr::U8 red, rdr::U8 green, rdr::U8 blue,
-                                ColourMap* cm) const
-{
-  if (trueColour) {
-    rdr::U32 r = ((rdr::U32)red   * redMax   + 127) / 255;
-    rdr::U32 g = ((rdr::U32)green * greenMax + 127) / 255;
-    rdr::U32 b = ((rdr::U32)blue  * blueMax  + 127) / 255;
-
-    return (r << redShift) | (g << greenShift) | (b << blueShift);
-  }
-
-  return pixelFromRGB((rdr::U16)(red << 8), (rdr::U16)(green << 8),
-      (rdr::U16)(blue << 8), cm);
-}
-
-
 void PixelFormat::bufferFromRGB(rdr::U8 *dst, const rdr::U8* src,
                                 int pixels, ColourMap* cm) const
 {
@@ -594,6 +545,17 @@
     if ((blueMax & (blueMax + 1)) != 0)
       return false;
 
+    /*
+     * We don't allow individual channels > 8 bits in order to keep our
+     * conversions simple.
+     */
+    if (redMax >= (1 << 8))
+      return false;
+    if (greenMax >= (1 << 8))
+      return false;
+    if (blueMax >= (1 << 8))
+      return false;
+
     totalBits = bits(redMax) + bits(greenMax) + bits(blueMax);
     if (totalBits > bpp)
       return false;