The auricles in wheat are defined as the clasping appendages or the claw-like projections that are located at the junction of a leaf sheath and the leaf blade. Auricles in combination with the shape of the ligules are two anatomical features used to distinguish grassy species from another, such has in this identification key.
The auricles on most of our wheat and barley varieties are pale green. A few recent releases have purple auricles. Below is a close-up picture of the auricles on the cv. 'Faller'. This coloring is the result of the presence of anthocyanins and is a heritable trait. Expression of the trait is, however, not stable and you may find different levels of coloring from year to year. There is no reason to be concerned about this coloring.