Hakonechloa - there's a plain green one, but I prefer the variegated yellow and green one, looks not unlike a short bamboo, but with floppier stems.

Festuca ovina glauca 'Elijah Blue' is a nice "blue" one for contrast, Imperata cylindrica 'Red Baron' (Japanese Blood Grass) is another popular one with red tipped leaves, Carex buchananii (Leather-Leaf Sedge) has bronze leaves, Milium effusum 'Aureum' is yellow.

Have a look at 'Worlds End Garden Nursery' site.
This nursery stocks a vast range of grasses of all shapes and sizes, it'll give you some ideas.
I buy from them and they're a company i'd recommend.

Or Knoll Gardens - they win gold medals at Chelsea and they specialise in grasses.

Have you looked at the GOYpedia pages under 'G' for grasses?

Thanks I will look