colorize user names under messages

src/widgets/letter-tile.jsx

@@ -2,7 +2,7 @@ import React from 'react';
 
 import Tinode from 'tinode-sdk';
 
-import { stringHash } from '../lib/strformat.js';
+import { idToColorClass } from '../lib/strformat.js';
 import { sanitizeImageUrl } from '../lib/utils.js';
 
 export default class LetterTile extends React.PureComponent {
@@ -10,8 +10,7 @@ export default class LetterTile extends React.PureComponent {
     let avatar;
     if (this.props.avatar === true) {
       const isGroup = (Tinode.topicType(this.props.topic) == 'grp');
-      const iconColor = (isGroup ? 'light-color' : 'dark-color')
-        + (Math.abs(stringHash(this.props.topic)) % 16);
+      const iconColor = idToColorClass(this.props.topic, isGroup);
       if (this.props.topic && this.props.title && this.props.title.trim()) {
         const letter = this.props.title.trim().charAt(0);
         const className = 'lettertile ' + iconColor;