<select class="classColor" @change="select" v-model="selectValue">
<option v-for="(itema, index) in classSelect" :key="index" v-text="itema.class_name" :value="itema.id"></option>
</select>
<select class="classColor" @change="select" v-model="selectValue">
<option v-for="(itema, index) in classSelect" :key="index" v-text="itema.class_name" :value="itema.id"></option>
</select>