I know the grasses can be a challenge to ID, but thought I'd give it a whirl. I photographed four variegated species over the weekend which were all approximately 12" or less in height and this is the third of them. All were on display at local public gardens so I presume they may be cultivars available in local nurseries in upstate NY area.

This particular grass was situated in full sun alongside perennial geraniums and a clump of miscanthus. It has been a bit dry in NY and it did appear to be showing some browning possibly as a result. It was still likely receiving more natural water than the others due to placement.