The rabbeim there used to fight the Rosh Hayeshiva ZT”L on this issue all the time. 15 years ago they were saying that the only other yeshiva that allowed colored shirts was Yeshiva of Flatbush. I understand why they are doing it, with the shortage of parents with enough seichel to understand that wearing white shirts does not make one a better talmid chochom. However, it’s a sad day when a Chofetz Chaim branch is forced to change the mesorah to match shallow perceptions. And it’s a sad reflection on the Flatbush community that colored shirts are viewed in the same light as jeans. No wonder so many kids have a shallow view of Yiddishkeit- it’s about the shirt color, not the inner penmimiyus.
Rabbi Harris’s sons all went “yeshivish”. One day rabbi Harris was sending a package of white shirts to one of his osns. He called them “Shabbos shirts”.