grayscale
0
1
2
3
4
5
<--add a filter class to body tag-->
+ <body class="filter">
<div>
<div class="v-grayscale-0">
</div>
<div class="v-grayscale-1">
</div>
<div class="v-grayscale-2">
</div>
<div class="v-grayscale-3">
</div>
<div class="v-grayscale-4">
</div>
<div class="v-grayscale-full">
</div>
</div>
filter-grayscale version