colors: [
    "#FFB5C5",
    "#EEC900",
    "#D1EEEE",
    "#40E0D0",
    "#FFFF00",
    "#FF7F00",
    "#FF6A6A",
    "#B3EE3A",
    "#9F79EE",
    "#FFC1C1"
   ],
   keywordsdetail: ["好看", "美丽", "wfewf"],
   comments: [
    {
     text: "老师 好看好看222"
    },
    {
     text: "老师美丽11111极了"
    },
    {
     text: "老师太搞笑34234了"
    },
    {
     text: "老师搞笑的不的了"
    },
    {
     text: "老师:ox::beer:wfewf啊"
    }
   ]

<span
    v-for="(item,index) in keywordsdetail"
    :key="index"
    class="keyworditem"
    :style="{backgroundColor:colors[index]}"
    @click="showpartkey(index,comments)"
   >{{item}}</span>

changeColor(resultsList, keywords) {
   keywords.map((keyitem, keyindex) => {
    resultsList.map((item, index) => {
     if (keyitem && keyitem.length > 0) {
      // 匹配关键字正则
      let replaceReg = new RegExp(keyitem, "g");
      // 高亮替换v-html值
      let replaceString =
       '<span class="highlight"' +
       ' style="color: ' +
       this.colors[keyindex] +
       ';">' +
       keyitem +
       "</span>";
      resultsList[index].text = item.text.replace(
       replaceReg,
       replaceString
      );
     }
    });
   });

   this.comments = [];
   this.comments = resultsList;
  }

let replaceString = '<span class="highlight"' +' style="color: ' + this.colors[keyindex] + ';">' + keyitem + "</span>";

<span class="highlight">keyitem</span>

.highlight {
color:red
}

.aaa >.highlight{
color:red
}