Change the value of the quota/price ceiling/subsidy/tax. The graph will automatically display the consumer surplus in green, the producer surplus in blue, and the government surplus (if any) in orange. In the specific case of a subsidy, the deadweight loss will be displayed in red.
Tip
For quota and price ceiling, you can also change the value of the quota/ price ceiling by clicking and dragging the enlarged red label that shows the quota/ price ceiling on the graph itself.