group-pm: fix colorHashFromString

colorHashFromString() now considers all charecters in the string
it can also now return colors with no red component in it. Also fixed
the cases where the function returned #NaN for very long or
empty strings.

Fixes: #3985

src/utils/color.js

@@ -7,14 +7,14 @@ export const foregroundColorFromBackground = (color: ColorValue): 'black' | 'whi
 
 export const colorHashFromString = (name: string): string => {
   let hash = 0;
-  for (let i = name.length - 1; i >= 0; i--) {
-    hash = hash * 31 + name.codePointAt(i);
+  for (let i = 1; i < name.length; i++) {
+    hash = hash * 31 + name.charCodeAt(i);
     hash %= 0x1000000;
   }
 
   let colorHash = hash.toString(16);
-  while (colorHash.length < 6) {
-    colorHash += '0';
-  }
+  colorHash = colorHash.padEnd(6, '0');
+  colorHash = colorHash.substring(3) + colorHash.substring(0, 3); // 3 Left Cyclic Shifts
+
   return `#${colorHash}`;
 };