How to remove css property in jQuery

You can remove them by:

$(".icha0").css({ 'background-color' : '', 'opacity' : '' });

You can use .css() to remove css property as well, like this:

$(".icha0").css("background-color","");
$(".icha0").css("opacity","");

As mentioned in the jquery documentation:

Setting the value of a style property to an empty string — e.g. $('#mydiv').css('color', '') — removes that property from an element if it has already been directly applied,