Remove background color from styled <legend>
Remove background color from styled <legend>

Fixes #10254.

Removing the colour makes no difference to the display and allows the element to be placed on areas with different background colours without having to override the element's CSS.

Owlbertz/foundation,aoimedia/foundation,ucla/foundation-sites,jamesstoneco/foundation-sites,dragthor/foundation-sites,DaSchTour/foundation-sites,dragthor/foundation-sites,jaylensoeur/foundation-sites-6,denisahac/foundation-sites,denisahac/foundation-sites,DaSchTour/foundation-sites,abdullahsalem/foundation-sites,jaylensoeur/foundation-sites-6,Owlbertz/foundation,zurb/foundation-sites,ucla/foundation-sites,IamManchanda/foundation-sites,dragthor/foundation-sites,zurb/foundation-sites,atmmarketing/foundation-sites,aoimedia/foundation,colin-marshall/foundation-sites,jamesstoneco/foundation-sites,IamManchanda/foundation-sites,aoimedia/foundation,zurb/foundation,denisahac/foundation-sites,colin-marshall/foundation-sites,colin-marshall/foundation-sites,abdullahsalem/foundation-sites,atmmarketing/foundation-sites,IamManchanda/foundation-sites,jamesstoneco/foundation-sites,abdullahsalem/foundation-sites,atmmarketing/foundation-sites,zurb/foundation,zurb/foundation-sites,Owlbertz/foundation,ucla/foundation-sites,zurb/foundation,jaylensoeur/foundation-sites-6,Owlbertz/foundation