Oil and water = two elements, factors or people that do not agree or blend together.

See the color of someone´s money = receive some evidence of forthcoming payment from a person.

Up the river = to or in prison.

Sell someone down the river = betray someone, especially so as to benefit oneself.

Coals to Newcastle =something brought or sent to a place where it is already plentiful.

Heap coals of fire (up) on someone´ s head =go out of one´s way to cause someone to feel remorse.

Remorse =regret, contrite

A piece of cake=something easily achieved.

A slice of the cake= a share of the benefits or profits.

Man cannot live by bread alone=people have spiritual as well as physical needs.

Want one´s bread buttered on both sides = want more than is practicable or than is reasonable to expect.

Break bread with = share a meal with someone.

Know (on) which side one´s bread is buttered =know where one´s advantage lie.

In the red = in debt, overdrawn, losing money.

Overdrawn = debit

In the black = not owing any money, solvent.

Solvent= having enough money to pay your debts.

Red letter day = happy day.

The green-eyed monster = jealousy.

A blue-eyed boy = the favorite of someone in authority.

Know how many beans make five= be intelligent.

Not (have) a bean= (be) penniless.

Penniless= without any money at all.