South-facing rooms get the kindest light in the house: bright, warm and steady from late morning through to evening. That warmth pushes everything a touch sunnier, which is why these rooms are the easiest to decorate — you can be bolder, cooler and richer than you'd dare elsewhere.
The practical upshot: warm colours can tip too far. A peachy pink like Farrow & Ball Setting Plaster that looks gorgeous in a north room can read almost orange in full south sun. Same with strong yellows and terracottas — they amplify. So if you want warmth without it shouting, you've got room to dial it back.
Where south light really earns its keep is with cooler colours. Greys, blues and greens that turn cold and flat on a north wall come alive here. Pavilion Gray holds its soft architectural grey beautifully, Mizzle keeps its green-grey freshness without going dingy, and a deep blue like Hague Blue looks properly luxurious rather than murky. Even crisp whites like Little Greene's whites or Benjamin Moore stay clean rather than glaring — though watch the brightest whites, as strong sun can make them feel a bit clinical.
The "but what about" question I always get: *won't it fade?* South light carries the most UV, so over years you can get fading on cheaper paints and on certain pigments (deep reds and some organic blues are the usual suspects). Stick to quality acrylic emulsions from any of the supported brands and you'll be fine — F&B, Little Greene and Benjamin Moore all hold up well.
Practical advice: because the light shifts so much across the day, sample big — at least A4 boards — and view them morning, midday and evening before committing. South rooms tempt you into something too warm at the shop; the daylight does half the warming for you, so go a notch cooler or more muted than your gut says. You'll thank yourself by teatime.