diff --git a/dither4.js b/dither4.js
index 9cff868..f0f38e5 100644
--- a/dither4.js
+++ b/dither4.js
@@ -398,6 +398,12 @@ function decimate(input, palette, n) {
         let least = Infinity;
         let pick = -1;
         for (let i = 1; i < decimated.length; i++) {
+            if (i == 0) {
+                continue; // keep black always
+            }
+            if (decimated[i].r == 255 && decimated[i].g == 255 && decimated[i].b == 255) {
+                continue; // keep white always
+            }
             if (popularity[i] < least) {
                 pick = i;
                 least = popularity[i];
@@ -405,9 +411,6 @@ function decimate(input, palette, n) {
         }
         let old = decimated.length;
         decimated = decimated.filter((rgb, i) => {
-            if (i == 0) {
-                return true; // keep black always
-            }
             if (i == pick) {
                 return false;
             }
@@ -417,6 +420,8 @@ function decimate(input, palette, n) {
             return true;
         });
         if (decimated.length >= old) {
+            console.log(decimated);
+            debugger;
             throw new Error('logic error');
         }
     }