diff --git a/dither-image.js b/dither-image.js
index d8ae0c4..e39b5ea 100644
--- a/dither-image.js
+++ b/dither-image.js
@@ -430,6 +430,7 @@ function decimate(input, palette, n, inputError) {
             if (inputError) {
                 rgb.inc(inputError[x]);
             }
+            rgb.cap();
 
             // find the closest possible color
             // @todo consider doing the difference scoring in luminance and hue spaces
@@ -475,6 +476,15 @@ function decimate(input, palette, n, inputError) {
 
 
     let decimated = palette.slice();
+    
+    // force to grayscale
+    //decimated = [0, 5, 10, 15];
+
+    // force to rgb
+    //decimated = [0, 0x36, 0xb6, 0x86];
+
+    // force to rWb
+    //decimated = [0, 0x36, 0x0f, 0x86];
 
     while (decimated.length > n) {
         let {popularity, fitness, output} = dither(decimated);