[Build] Run build, remove useless colours

build/helpers/render.js

@@ -11,6 +11,7 @@ const build = ( wallpaper, lockpaper, theme ) => {
     console.log( '\n=> Extracting colours' );
     // Extract colour palette from chosen wallpaper using Color-Thief
     colorThief.getPalette( wallpaper ).then( palette => {
+        palette = util.removeUselessColours( palette );
         // Define view options (for rendering with mustache)
         if ( theme === 'test' ) {
             palette = [ [ 255, 0, 0 ], [ 0, 255, 0 ], [ 0, 0, 255 ] ];

build/helpers/util.js

@@ -57,6 +57,22 @@ const renderColourAsRGBAHex = ( colour, ambiance ) => {
     return `rgba(${hexCol}${decimalToHex(ambiance)})`.toLowerCase();
 }
 
+const removeUselessColours = ( palette ) => {
+    const p = [];
+    for ( let i = 0; i < palette.length; i++ ) {
+        const luminance = calculateLuminance( palette[ i ] );
+        if ( luminance < 215 && luminance > 40 ) {
+            p.push( palette[ i ] );
+        }
+    }
+
+    return p;
+}
+
+const calculateLuminance = ( colour ) => {
+    return colour[ 0 ] + colour[ 1 ] + colour[ 2 ] / 3;
+}
+
 
 /*
  * Replace the colours with variable names
@@ -149,5 +165,6 @@ module.exports = {
     renderColourAsRGBHex,
     renderColourAsRGBAHex,
     themePreProcessor,
-    getGradientColour
+    getGradientColour,
+    removeUselessColours
 }