how to make a split icon dark (theme-b) while the split is light (theme a)?

how to make a split icon dark (theme-b) while the split is light (theme a)?

Hi:

For a listview, I can add a second link to make a split button.

In version 1.3.2, if i do
<ul data-role="listview" data-theme="d" data-inset="false" data-split-icon="gear" data-split-theme="a"></ul>
here theme "a" is dark, theme "d" is light, the icon is black on a white button.

but in version 1.4.2, it does not work, either both the split button and the icon are black, or both are light color.

I have tried various ways, such as make the icon and button both dark with data-split-theme="b" and remove class ui-btn-b from the link. then the icon is of light color again.

is there a way to make the icon black and button light color?

thanks a lot.