<div class="personal_form-item">
<p class="personal_form-text">
Доп. телефон:
</p>
<select name="#" class="personal_form-select_choise">
<option disabled selected="selected">Выберете Ваш пол</option>
</select>
</div>
select {
color: green;
}
//
.personal_form-select_choise {
color: green;
}
select option[value="1"] {
color: green
}
//
.personal_form-select_choise option[value="1"] {
color: green
}
<option value="1">новый предмет</option>