Posted: 08/09/2016 at 15:53
Ajuga reptans purp. is low growing ground cover - blue flower spikes in Spring/early summer with dark purple foliage. Vinca minor is also an evergreen ground cover. Plain green foliage with light blue or purple flowers or variegated (green/yellow) foliage with slightly darker blue flowers. There is also a form of Dianthus which is matt forming - produces tiny pink or white flowers from late Spring to early summer.
Try looking up evergreen ground cover plants and see if there are more which fit your site/conditions there are new plants coming on the market all the time