如何在ms word較background color or pattern?

under format -- border and shading can only have colour on the paragraph.
use insert picture or box under the header, make a whole page colour box or insert a picture in half tone.
view -- header and footer -- draw a rectangle, format its size to the page (A4 postrate = 29.7 cm height × 21 cm width), set colour and no border, format the layout to centre page and top to page. press OK --- exit the header.
view -- header and footer -- insert picture from file, format its size to the page (A4 postrate = 29.7 cm height × 21 cm width, may need to distort the aspect ratio), set layout : behind text, format the layout to centre page and top to page. OK, format the picture to washout under colour, press OK --- exit the header.