fix: node 6 compatibility, take 2 (#353)

src/parseToRgba.ts

@@ -73,7 +73,7 @@ const compressedColorMap = '1q29ehhb 1n09sgk7 1kl1ekf_ _yl4zsno 16z9eiv3 1p29lhp
     const key = colorToInt(next.substring(0, 3));
     const hex = colorToInt(next.substring(3)).toString(16);
 
-    // NOTE: pad start could be used here but it breaks Node 6 compat
+    // NOTE: padStart could be used here but it breaks Node 6 compat
     // https://github.com/ricokahler/color2k/issues/351
     let prefix = '';
     for (let i = 0; i < 6 - hex.length; i++) {

src/toHex.ts

@@ -6,7 +6,14 @@ import guard from './guard';
  */
 function toHex(color: string): string {
   const [r, g, b, a] = parseToRgba(color);
-  const hex = (x: number) => guard(0, 255, x).toString(16).padStart(2, '0');
+
+  let hex = (x: number) => {
+    const h = guard(0, 255, x).toString(16);
+    // NOTE: padStart could be used here but it breaks Node 6 compat
+    // https://github.com/ricokahler/color2k/issues/351
+    return h.length === 1 ? `0${h}` : h;
+  };
+
   return `#${hex(r)}${hex(g)}${hex(b)}${a < 1 ? hex(Math.round(a * 255)) : ''}`;
 }