Evolvulus glomeratus (sometimes listed as Evolvulus pilosus) has grey-green foliage and small blue flowers. There is also a white-flowered form.
This is a popular species for landscaping because of its toughness. It's used as a low shrubby plant in a mixed bed or planted en masse as a groundcover.
Like most flowering species it isn't suitable for constant clipping if you want to retain the flowers. However, it needs to be cut well back from time to time to keep it fresh and compact and looking good.