Teams changing color of thier undershirts

[RJB44]

Just curious to know if the decision to change color of undershirt is made as a formal management decision or is this more of an informal decision made in the clubhouse with Manager's approval?

During 70s the Oakland A's had always worn green sleeves under the white jerseys, when Billy Martin came, they started wearing white sleeved shirts under the same white jeresys.

During the 1980s the Red Sox had always worn navy sleeves under their white a grey jerseys, then switched to red?

[dnrapp]

Just curious to know if the decision to change color of undershirt is made as a formal management decision or is this more of an informal decision made in the clubhouse with Manager's approval?

During 70s the Oakland A's had always worn green sleeves under the white jerseys, when Billy Martin came, they started wearing white sleeved shirts under the same white jeresys.

During the 1980s the Red Sox had always worn navy sleeves under their white a grey jerseys, then switched to red?

In the A's case Billy Martin make the change.