optgroup element is not themed.

[jgossett]

When you create a non-native list with optgroup, there is no way to change the divider theme. And, the current implementation has the divider theme very similar to the selected item theme. I would assume data-divider-theme would change the optgroup theme.

<select data-divider-theme="e" data-native-menu="false" id="SelectedTheme" name="SelectedTheme"><optgroup label=""></optgroup>
<optgroup label="Basic"><option selected="selected" value="Default">Default</option>
<option value="Blocks">Blocks</option>
<option value="Bubble">Bubble</option>
<option value="Floating">Floating</option>
<option value="Minimalist">Minimalist</option>
<option value="Modern">Modern</option>
<option value="Words">Words</option>
</optgroup>
<optgroup label="Kids">
<option value="Bugs">Bugs</option>
<option value="Construction">Construction</option>
<option value="Meadow">Meadow</option>
<option value="Ocean">Ocean</option>
<option value="Rainforest">Rainforest</option>
</optgroup>
</select>

[jaspermdegroot]

Related PR: #4812

[jaspermdegroot]

New PR: #5033

[jaspermdegroot]

PR #5033 has been merged. Closing as fixed.