Parent Anne-Marie Alder said she had been told her children's shoes are now "acceptable" by Baverstock Academy.
The school in Druids Heath, Birmingham, implemented a new rule on Tuesday to make plain black shoes compulsory.
Some parents said the policy was harsh but the school said ample notice was given.
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Ms Alder, from Druids Heath, said two of her children had been told their "polishable" shoes were now suitable, and her Year 11 daughter who is sitting exams and wore trainers had been loaned a pair by the school.
She said she was not given an explanation as to why the shoes were now deemed acceptable.
Ms Alder said the "ridiculous" decision on Tuesday had led to "chaotic" scenes and about 300 children were sent home.
Another parent, whose daughter was sent home but could not attend on Wednesday due to a hospital appointment, said she will be sending her daughter to school in the same shoes regardless of whether they are accepted.
Baverstock Academy would not say how many pupils were sent home on Tuesday and has not commented about why Mrs Alder's children's shoes are now acceptable.
Defending the initial decision to send pupils home, interim executive principal Sylvia Thomas said enough notice of the changes had been given, adding parents had given their support to her over the new rules.
Two pupils sent home from school for wearing incorrect shoes have been allowed to return with the same footwear, a parent said.