20 years ago, few newspapers printed copies with four-color printing because of the technical limitations of the pre-press and printing press. Since the introduction of computerized pre-press systems and automated plate-making and printing equipment, you probably see four-color items on most newspaper everyday.
Once the color reproduction process required experts. Now computerized color processing technology makes it editors' jobs. They choose a favorite picture on a display screen and then hit a command button to transmit it to a designated page. When the development of a new advertisement system is completed, which gets originals with digital form via web from advertisement agencies, process time required for putting an advertisement on a page will be shortened and the quality of printings would be better.
Japanese newspapers utilize offset presses for four-color printing in general. Satellite type machines were dominant in the past. A tower type machine appeared in the Japanese market 4 to 5 years ago and it thrives at present for the space efficiency and more color pages.