I cannot stand either Theresa May or Nicola Sturgeon but the last thing I would ever criticise is what they wear.
I actually think both of them dress in an appropriate way for a female politician. I have noticed that Sturgeon more often wears bright colours - like the Queen, in order to be noticed, and May more often wears navy, grey and black jackets, a bit more like a male politician, but I think they both get their looks right, insofar as they can.
Actually I prefer the "uniform" of Angela Merckel, usually black trousers and a coloured tailored jacket which does the job opf projecting her image.