That's the article that the Jerusalem Post cited.Students attending protest told to 'wear blue' to mark them as 'colonizers'
Students forced to take part in a protest were allegedly asked by teachers to wear blue shirts to identify them as "colonizers."torontosun.com
A more reasonable source:
Largest school board in Ontario under fire after field trip to downtown protest | Globalnews.ca
The Toronto District School Board is under fire after a field trip to a 'day of action' in support of Grassy Narrows delivered students to what became an Israel-Gaza protest.
globalnews.ca
Ontario’s largest school board is under fire after students at several schools were taken on a field trip where they appear to have ended up taking part in a protest held in downtown Toronto.
Students at a number of Toronto District School Board schools were given permission to head to a day of action for the people of Grassy Narrows First Nation on Wednesday, whose community river was impacted by years of mercury poisoning.
The board said a trip to view a protest by Grassy Narrows that had promised to attract thousands outside Queen’s Park was “an educational experience for students to hear from Indigenous voices about the ongoing challenges faced by the people of Grassy Narrows.”
Some parents and other groups, however, complained the trip veered away from education and into protest and activism.
[...]
“There were people in masks, people donning keffiyehs, showing signs about the Israel-Gaza war. This was a protest — and this is not the messaging that teachers put on information to parents about what they were doing.”
The school board itself admitted the event had not played out as expected and said an internal review would take place.
“We understand that issues beyond the main focus of this event were raised and that some students may have been negatively impacted by what they saw and heard,” TDSB said in a statement.
“The TDSB was not aware that students would engage with any issues outside of the main focus… and we apologize for the harm that some students may have experienced as a result. At this time, we are supporting impacted students and their families.”
The board's own statement: News: A Statement from Neethan Shan, Acting Chair on the school trip to the Grassy Narrows River Run event | Toronto District School Board
I think it seems strange that the staff involved didn't realize that the event would be a protest. This seems pretty clear from the promotional material for the event:
... so some questionable decisions seem to have been made, but it seems like the presence of anti-Israel protestors at the event was something that they legitimately didn't - and couldn't - foresee.