Those 4 coloured dots show the colors printed on the newspaper. On the front page, they appear at the bottom of the newspaper but also on the top of the inside pages. Double pages also have + signs. The above dots and + symbols are known as the registration marks. + symbol is used for cutting correctly. 4 separate colour ink drums and 4 separate rollers are used for the 4 colors to fed the colour used in an image. When they arrive at the correct locations, a beautiful picture is formed and registration marks are put to check it. Currently, CMYK (CMYK stands for Cyan Blue, Magenta Pink, Yellow, and Black) is a color scheme used to print newspapers and posters, etc. That is why the registration marks of those four colors are given as dots. Such dots do not appear on the page where only black letters and black and white images are printed.
small drops make a mighty ocean