feat(style): update basic red color (#4368)

src/dropdown-menu/README.md

@@ -82,7 +82,7 @@ export default {
 Use `active-color` prop to custom active color of the title and options
 
 ```html
-<van-dropdown-menu active-color="#f44">
+<van-dropdown-menu active-color="#ee0a24">
   <van-dropdown-item v-model="value1" :options="option1" />
   <van-dropdown-item v-model="value2" :options="option2" />
 </van-dropdown-menu>

src/dropdown-menu/README.zh-CN.md

@@ -84,7 +84,7 @@ export default {
 通过`active-color`属性可以自定义菜单标题和选项的选中态颜色
 
 ```html
-<van-dropdown-menu active-color="#f44">
+<van-dropdown-menu active-color="#ee0a24">
   <van-dropdown-item v-model="value1" :options="option1" />
   <van-dropdown-item v-model="value2" :options="option2" />
 </van-dropdown-menu>

src/dropdown-menu/demo/index.vue

@@ -43,7 +43,7 @@
     </demo-block>
 
     <demo-block :title="$t('customActiveColor')">
-      <van-dropdown-menu active-color="#f44">
+      <van-dropdown-menu active-color="#ee0a24">
         <van-dropdown-item
           v-model="value1"
           :options="option1"