Peterson ministry

The Peterson ministry was the combined cabinet that governed Ontario from June 26, 1985, to October 1, 1990. It was led by the 20th Premier of Ontario, David Peterson. The ministry was made up of members of the Ontario Liberal Party, which commanded a first a minority and later a majority in the Legislative Assembly of Ontario.
The ministry replaced the Miller ministry following the 1985 Ontario general election, which resulted in the Progressive Conservative Party of Ontario winning a plurality of seats, but ultimately failing to secure the confidence of the legislature. The Peterson ministry governed through most of the 33rd Parliament of Ontario and all of the 34th Parliament of Ontario.
After the New Democratic Party secured a majority in the 1990 Ontario general election, Peterson resigned, and was succeeded as Premier of Ontario by Bob Rae.

History

The Peterson Ministry is formed

Premier Peterson assembled a cabinet of 23 ministers, which was sworn in on June 26, 1985, shortly after the Miller ministry fell to a vote of non-confidence in the Ontario Legislative Assembly.
Elinor Caplan, was the first Jewish woman to serve in ministry in Canada, at either the federal or provincial level
There were 26 portfolios at the beginning of the Peterson ministry. There were several instances of ministerial portfolio reorganisation as Peterson took over from Miller:

Three portfolios were eliminated, as the Provincial Secretariats of Justice, Social Development, and Resource Development that had been created in the early 1970s during the Davis ministry were terminated.
Solicitor General and Ministry of Correctional Services were combined into "Solicitor General and Ministry of Correctional Services"
Ministry of Municipal Affairs and Housing was divided into a "Ministry of Housing" and a "Ministry of Municipal Affairs"
Ministry of Northern Affairs was renamed "Ministry of Mines and Northern Affairs".
Ministry of Industry and Trade was renamed "Ministry of Industry, Trade and Technology."

Within a year, Premier Peterson would create a new portfolio:

Ministry of Financial Institutions was created April 1, 1986.

Thus by mid-1986 the number of cabinet members would thus dwindle to 21, even as the number of portfolios grew to 27.

1987 Post-election Shuffle

The Peterson ministry underwent a significant restructuring following the 1987 Ontario general election, in which the Ontario Liberal Party improved from minority status to a majority, securing 95 out of 130 seats. A significantly larger caucus portended a significantly larger cabinet, and an end to the situation in which so many cabinet members had to helm multiple portfolios.
None of the incumbent cabinet ministers lost their seats in the election, though three were dismissed by Peterson to the backbenches.
There were several instances of ministerial portfolio reorganisation:

Ministry of Citizenship and Culture and Ministry of Transportation and Communication were reorganised into Ministry of Citizenship, Ministry of Culture and Communication, and Ministry of Transportation.
Ministry of Northern Development and Mines was divided into Ministry of Northern Development and Ministry of Mines.
Solicitor General and Minister of Correctional Services was divided into "Solicitor General" and "Minister of Correctional Services".

Thus the number of portfolios increased to 30, as did the number of cabinet members.

1989 Midterm Shuffle

There was one instance of a ministerial portfolio reorganisation:

Ministry of Municipal Affairs and Ministry of Housing was combined into "Ministry of Municipal Affairs and Housing".

The number of women would fall to five, but at last the Minister Responsible for Women's Issues would for the first time actually be a woman.
Thus, as the election of 1990 approached, the Peterson ministry contained 25 cabinet members in 29 portfolios.

Election of 1990

Alas, the Liberal Party lost 59 seats, falling to 36, surrendering the majority to the NDP, and the Peterson ministry was forced to resign.

Summary

There were 38 people who served in the Peterson ministry.
Eight were women.
At no point was the ministry all-white.