<a href="abc.html" onMouseOver="this.style.color='#0F0'" onMouseOut="this.style.color='#00F'" >Text</a>
document.getElementById("mydiv").onmouseover= function(e){this.className += ' my-special-class'; }; document.getElementById("mydiv").onmouseleave= function(e){this.className = this.className.replace('my-special-class',''); };
document.head.insertAdjacentHTML('beforeend', '<style>#mydiv:hover{color:red;}</style>');