NS,Ch12 � The Yellow Ajah quarters in the White Tower are decorated in flamboyant style compared to other Ajahs.
NS,Ch14 � The Blue Ajah is also a bit at odds with the White and Yellow over something in Altara a hundred years before. The Brown Ajah supports the White against the Blue, but supports the Blue against the Yellow.
TEotW,Glossary - The glossary lists the colors of the seven Ajahs. This is the first mention of the Yellow Ajah.
TEotW,Glossary - Yellow Ajah sisters bond only one Warder at a time.
TSR,Ch5 - Yellow sisters are the best Healers. They will try to learn to Heal anything.