How do I get her shirt to be white?

Yesterday was the Musical Evening at S & R's school. It was quite an impressive event, there are some very musically talented children attending the school. Rushil's class sang a song. Somewhere in the middle of the song, Rushil stopped singing. Later when I asked him why, he said he was embarrassed as one of his friends was sitting in the front row and he was distracted. He did however take the opportunity to whisper hello into the microphone before the song started in front of a full audience. To add to that, his best friend's older brother, note OLDER brother praised Rushil not for his singing but that he said hello into the mike. Rushil was of course pleased with himself as there is nothing like getting praised by an older kid. Sindhu was part of the choir and they sang 2 lovely Italian songs, a couple of English songs and a rock song "We will, we will rock you", it was a big hit with the kids. Although Sindhu did sing all the songs, she was turning to the right or left to check out the audience, and never focussed towards the center, you can even this in the pictures :-) Sindhu was very excited about singing in the show and practiced quite a bit at home.

Have you seen the noticeable difference in the colour of Sindhu's uniform as compared to the others? That's her formal uniform and they don't have to wear it during the summers because it's so hot except on special occasions. All 4 of her shirts are this murky colour and I was attributing it to the poor water quality in India but if you look closely, all the other kids have crisp white shirts. Where did I go wrong? I seriously have no idea. Today I spent a good part of the day soaking 2 of the shirts in bleach but they still look murky. Monday is picture day and her teacher warned her that her shirt had to be white. I seriously need help, I asked the maid and she just shrugged her shoulders. The bad part is, that all of her white shirts have become like this. Help!?!