Colony Policies are a way for players to add bonuses and maluses to their colonies. They affect colonies individually. They go into effect the month after they are enacted (same time as monthly crew/marine pay and industry profit/loss) if they aren't policies that have longer delays.
Each colony has it's own amount of policy points. All colonies have minimum colony points equal to one third of their size (rounded down) by default. Having an administrator grants one point starting from next month after they're appointed. Each admin skill grants one point starting from next month after they're gained (maybe one point per two skills if that's too much). Points can be purchased with credits, cost goes up with planet size. They can be gained from enacting some policies, amount gained depending on the policy.
Policies can have conditions required before they're enacted, like min/max hazard ratings, min/max population size, presence or absence of industries etc.