Apparently there is a time limit set by some one, I don't really know who. You may colonize some native peoples if your country is strong (eg China, Britain). However you must do it within certain unwritten mode and time constraints. Otherwise it will end up like New Zealand. Captain Cook landed at the Bay of Plenty (Tauranga), planted the Union Jack and claimed this land for the Queen. Even today we have a governor general in Wellington, representing the Queen!
There is a slight difference in this case (from Sarawak). NZ is not considered a colony of Britain. It is one of the commonwealth countries (same as Australia and Canada). Also during the colonization process, Maori fought the British and won many battles both in the Waikato and elsewhere. Both parties ended the conflict by signing a treaty of peace at Waitangi.
Now in NZ we have a very unique situation. The Union Jack is included in a small corner of our flag; but we are not exactly a British colony. What are we? Maori control huge pieces of land and other resources like water. They also hold certain special privileges in parliament. Resource consent must be obtained before any mega projects can proceed e.g. Off shore drilling, building of open cast mines, dams, wind generators etc.
*The Bakun dam never had agreement from the Ibans because they were colonized. The United States was a colony of Britain. They fought the wars of independence and won! That is the difference. Sorry about writing this piece with no dates. I was never a historian :)