I have a dark background for the pages on my site, achieved by system background colour of black and a dark image as background at system level.
(General Settings >Background)

But when page first visited or refreshed on browser (for example Chome) it appears as white until the page is properly displayed.

This ‘white flashing’ when move from page to page doesn’t look good. – check it out, refresh the browser!

a) How can I get it to be black in this transitionary period?

b) I noticed that when I build a new page the black background set at system level is overwritten by a white background to a new section and I have to go into the background settings for the section to set the colour to transparent – how can it automatically be transparent?