Some interesting tidbits from Wikipedia:

Activity that could be called colonialism has a long history, starting at least as early as the ancient Egyptians. Phoenicians, Greeks, and Romans founded colonies in antiquity. Phoenicia had an enterprising maritime trading-culture that spread across the Mediterranean from 1550 BC to 300 BC; later the Persian Empire and various Greek city-states continued on this line of setting up colonies. The Romans would soon follow, setting up coloniae throughout the Mediterranean, in North Africa, and in Western Asia.

The Japanese colonial empire began in the mid-19th century with the settler colonization of Hokkaido and the destruction of the island's indigenous Ainu people before moving onto the Ryukyu Islands (the indigenous Ryukyuan people survived colonization more intact). After the Meiji Restoration, Japan more formally developed its colonial policies with the help of European advisors. The stated purpose from the beginning was to compensate for the lack of resources on the main islands of Japan by securing control over natural resources in Asia for its own economic development and industrialization, not unlike its European counterparts. Japan defeated China in the First Sino-Japanese War to control Korea and the island of Formosa, now Taiwan, and later fought off the Russian Empire to control Port Arthur and South Sakhalin.

While colonies of contiguous empires have been historically excluded, they can be seen as colonies. Contemporary expansion of colonies is seen by some in case of Russian imperialism and Chinese imperialism. There is also ongoing debate in academia about Zionism as settler colonialism.

Of course, historical facts rarely matter when it comes to rhetoric like this.