Css3中hover动画的颜色动画怎么使用

html
<span>fade</span>
css
/当前元素设置相对定位/.ech-fade, .ech-fade-t, .ech-fade-b, .ech-fade-l, .ech-fade-r, .ech-fade-c-in, .ech-fade-m-in, .ech-fade-m-out, .ech-fade-c-out, .ech-bounce-t, .ech-bounce-b, .ech-bounce-r, .ech-bounce-l { position: relative; transition: all .3s; z-index: 1;

html
<span>overline-l</span>
css
/上划线和下划线变化 当前元素样式设置相对定位/.ech-overline-r, .ech-overline-l, .ech-underline-r, .ech-underline-l, .ech-underline-c, .ech-overline-c, .ech-underline-c-out, .ech-overline-c-out{ position: relative; transition: all .3s; z-index: 1;

html
<span>arrow-l</span><span>arrow-r</span><span>arrow-t</span><span>arrow-b</span><span>arrow-l</span><span>arrow-r</span><span>arrow-t</span><span>arrow-b</span>
css
.ech-arrow-l, .ech-arrow-r, .ech-arrow-t, .ech-arrow-b, .ech-arrow-l-move, .ech-arrow-r-move, .ech-arrow-t-move, .ech-arrow-b-move{ position: relative; transition: all .3s; z-index: 1;