Your suggestion is nice.

I would get a huge pot, plant a Grevillea rosmarinifolia/juniperina in the middle, I'd plant purple heather around the space between the grevillea and the edge and grow varigated ivy down the edges of the pot, with maybe festuca glauca between the heathers? You'd have plenty of colour from flowers and foliage.

Sarcococca hookeriana likes a bit of shade, and a south facing position might well be too sunny. What about Pieris, particularly the variegated leaf ones? Or Euonymus pictata.

addendum to Andrea's suggestion. If you do go for this combo (which sounds great), select the named form of Grevillea called Canberra Gem. My mums flowers from March to August up here in Northumberland.

Fractal, March to August doesn't provide much Winter interest. The Canberra Gem is a lovely specimen, but I'd choose one that will flower over the Winter. I have 3 types altogether, the rosmarinifolia or juniperina is the only information I have about the plants I have, the names like 'Canberra Gem' was not given. Mine flower throughout the colder months. When we had all the snow last Winter, mine were flowering away orange and red. Are you sure you don't mean August to March?

You could put heucheras they are evergreen and have fabulous colourful foliage all year round look great in pots
the Sarcococca (they smell great in the winter )could go at the back or in the middle and heucheras around the edge.
Then when Sarcococca gets larger (slow at start) move the Heuchera on to the border or into more containers.
Pick ones that like the sun such as Mahogany, Midnight rose, Marmalade etc.

Great idea, love heucheras myself = but again, they do like a bit of shade.

Andrea, no, Canberra Gem flowers when I said. I was thinking that the other plants you suggested would give winter colour and the Grevillea CG would give colour for a good part of the rest of the year.

The Grevillea juniperina is a great plant and does give flower over the colder months so perhaps is better suited to the original persons question. :-)

Not all heuchera need shade
Mahogany, Marmalade, blackberry jam caramel, peach flambe to name but a few love the sun in fact they get their best colour when in the full sun.
They will also grow in part shade but the co0lour on these vaireties is better in the sun.
Perect for south facing gardens.