How to make this button an effect when hovering, so that it would be clarified for example or light up in a different color?

<p align="right"> <script type="text/javascript"> var cfJsHost = (("https:" == document.location.protocol) ? "https://" : "http://"); document.write(unescape("%3Cscript src='" + cfJsHost + "cdn-main.123contactform.com/includes/tinybox/tinybox.js.minified.js?2dd7b05' type='text/javascript'%3E%3C/script%3E")); </script> <link href="//www.123contactform.com/includes/tinybox/tinyboxstyle.css.minified.css?2dd7b05" rel="stylesheet" type="text/css" /> <a href="javascript:" style="display:scroll;z-index:10;bottom:210px;left:2px;" onclick="var tinybox_width = window.innerWidth || document.documentElement.clientWidth; tinybox_width=Math.round(tinybox_width*0.6);TINY.box.show({iframe:'http://www.123contactform.com/form-2169330/-',boxid:'frameless',width:tinybox_width,height:500,fixed:false,maskid:'bluemask',maskopacity:40})"><img border="0" src="http://i.piccy.info/i9/acfb6e3f8f7771c1c4cd0c74a9822ec9/1472759469/599/1065900/PRYPer.gif"></a></p>

    1 answer 1

    "Enlightened":

     p { text-align: center; } a { display: inline-block; } a:hover { opacity: .75; } 
     <p align="right"> <script type="text/javascript"> var cfJsHost = (("https:" == document.location.protocol) ? "https://" : "http://"); document.write(unescape("%3Cscript src='" + cfJsHost + "cdn-main.123contactform.com/includes/tinybox/tinybox.js.minified.js?2dd7b05' type='text/javascript'%3E%3C/script%3E")); </script> <link href="//www.123contactform.com/includes/tinybox/tinyboxstyle.css.minified.css?2dd7b05" rel="stylesheet" type="text/css" /> <a href="javascript:" style="display:scroll;z-index:10;bottom:210px;left:2px;" onclick="var tinybox_width = window.innerWidth || document.documentElement.clientWidth; tinybox_width=Math.round(tinybox_width*0.6);TINY.box.show({iframe:'http://www.123contactform.com/form-2169330/-',boxid:'frameless',width:tinybox_width,height:500,fixed:false,maskid:'bluemask',maskopacity:40})"><img border="0" src="http://i.piccy.info/i9/acfb6e3f8f7771c1c4cd0c74a9822ec9/1472759469/599/1065900/PRYPer.gif"></a> </p>

    Color changes:

     p { text-align: center; } a { display: inline-block; text-decoration: none; } a:hover span{ background: red; } a span { display: inline-block; text-transform: uppercase; color: #fff; text-decoration: none; font-family: Tahoma; font-size: .67rem; height: 39px; line-height: 39px; width: 102px; text-align: center; background: #28292e; } a img { display: none; } 
     <p align="right"> <script type="text/javascript"> var cfJsHost = (("https:" == document.location.protocol) ? "https://" : "http://"); document.write(unescape("%3Cscript src='" + cfJsHost + "cdn-main.123contactform.com/includes/tinybox/tinybox.js.minified.js?2dd7b05' type='text/javascript'%3E%3C/script%3E")); </script> <link href="//www.123contactform.com/includes/tinybox/tinyboxstyle.css.minified.css?2dd7b05" rel="stylesheet" type="text/css" /> <a href="javascript:" style="display:scroll;z-index:10;bottom:210px;left:2px;" onclick="var tinybox_width = window.innerWidth || document.documentElement.clientWidth; tinybox_width=Math.round(tinybox_width*0.6);TINY.box.show({iframe:'http://www.123contactform.com/form-2169330/-',boxid:'frameless',width:tinybox_width,height:500,fixed:false,maskid:'bluemask',maskopacity:40})"> <img border="0" src="http://i.piccy.info/i9/acfb6e3f8f7771c1c4cd0c74a9822ec9/1472759469/599/1065900/PRYPer.gif"> <span>заказать звонок</span> </a> </p>