I wear black to weddings. You can get away with lots of rewears if you go with black and switch the accessories and footwear around. It obv does for funerals too.
I absolutely agree, TheOliphant. Her drama training really stands to her.
I liked both dresses today - I am not a huge fan of vertical stripes usually, but I think the dress managed to tick several boxes - a vaguely African print or colour scheme, casual-ish yet clearly a dress for an occasion, and not so bright or stunning (not by a long shot) that she overshadowed the honorees or the invited guests, which iirc is the whole purpose of the trip (i.e. that grassroots campaigners will get the spotlight).
The khaki green was perfectly appropriate for a respectful mosque visit. It was un-showy and modest without going overboard - voluminous fabric, good coverage, nondescript colour but one that suits her very well, neck open a little, sleeves not long, belted. It also had a sense of occasion to it - it was floor length and the fabric had a sheen to it.