While I myself do not have any problem with the colour scheme, I agree that some people might have a problem. In combination with e.g. a 15" monitor with 4k resultion some items are getting hard to read. LR is a bit better, as it uses e.g. different colourschemes for highlighted items. And light grey or white for the menubar items would be indeed better to read.

Ok, in the next update (5.5) the contrast in the tree will be increased and also the menus will show more contrast.