The difference of the Government Minimum Support Price (MSP) and market price, which is paid directly to the farmers under W.T.O. is called:

🛑Important Points:
Blue box subsidy:  Blue Box refers to a category of domestic support or subsidies under the WTO’s Agreement on Agriculture.
​Blue box supports are subsidies that are tied to programs that limit production. Hence it is an exception to the general rule related to agricultural support. The Blue box subsidies aim to limit production by imposing production quotas or requiring farmers to set aside part of their land. It covers payments directly linked to acreage or animal numbers (reduction).
​Amber Box subsidy: For agriculture, all domestic support measures considered to distort production and trade (with some exceptions) fall into the amber box. The total value of these measures must be reduced. Various proposals deal with how much further these subsidies should be reduced, and whether limits should be set for specific products rather than having overall “aggregate” limits.
Green Box Subsidy: The green box is defined in Annex 2 of the Agriculture Agreement. In order to qualify, green box subsidies must not distort trade, or at most cause minimal distortion. They have to be government-funded (not by charging consumers higher prices) and must not involve price support.