Still think berberis atropurpurea nana.....dwarf, purple berberis would do very well. But, santolina too? Silver grey, aromatic, accepts hard pruning and great as a hedge. There's a lovely Abelia called Comfetti. It grows to about 4 feet, has small variegated pale green n white leaves that have shades of pink in them. Has pale pink fragrant flowers. How about a mixture of dwarf shrubs? I have a "hedge" of potentilla, euonymous emerald n gold, golden privet, loniicera Baggesons gold, a bright blue flowered variety of rosemary, sarcoccoca, etc. with a couple of half standard prunus cistena crimson dwarf to punctuate it. You could spend time planning a nice combination to give colour all year round. A hedge doesn't have to be just one variety.....