for example, when you go to the page below with this code, upon load option one is selected and has a background color of grey. When I click it it turns blue. How can I have it that blue when the page loads, not grey.
<select class="select" multiple="multiple" id="select_id">
<option selected>option one</option>
<option>option 2</option>
<option>option 3</option>
</select>
You can override background color of selected value like this:
select option:checked{
background: lightgreen -webkit-linear-gradient(bottom, lightgreen 0%, lightgreen 100%);
}
<select class="select" multiple="multiple" id="select_id">
<option selected>option one</option>
<option>option 2</option>
<option>option 3</option>
</select>