Label color is not inheriting from body

I have a site with forms that uses jQuery UI ThemeRoller (http://jqueryui.com/themeroller/) for theming, and on Safari Preview and iOS 10, the labels have suddenly turned white.


The work on all other browsers (as they have for years).


When I inspect, it appears that the body color is being overridden by the ui-composition-content class, when previously it was not.


My workaround is to add a specific color tag for the labels, to reset them to body (which is what they should be):


label {
    color: #000000;
}


Any ideas on why the new Safari is no longer rendering as expected ?