Colours and north or south light

North light and south light are physically different, and this difference affects colour perception in measurable ways.

North light is diffuse, constant, never direct. It sits around 8000 to 10,000 K (very cool, pulling toward blue). It barely changes throughout the day. Studio painters love it because it is stable, but it flattens warm shades and accentuates cool ones.

South light is direct, variable, intense. It ranges between 4000 and 6500 K depending on the time. In the morning and evening it pulls toward gold (warm light). At midday it pulls toward neutral white. It warms all shades and creates contrast.

The same shade can therefore appear very different depending on orientation. It is physical, not subjective. This is why interior designers never give a colour recommendation without knowing the orientation of the room.

In a north-facing room. Light makes warm shades turn cool. A warm beige appears greyed. A terracotta appears brownish. An off-white appears bluish. Three strategies to compensate.

First strategy: choose decidedly warm shades to compensate for the cooling. Sandy beige, creamy off-white (never pure white), deep terracotta, honey yellow, warm powder pink. Avoid "borderline" shades that tip into coolness.

Second strategy: accept the cool character and amplify it. Deep teal, grey sage green, pearl grey. These shades flourish in cool light and give the room a contemplative character. It is a deliberate choice.

Third strategy: choose shades that contain both. Seafoam (blue pigment + green pigment), rosy off-white (red pigment + ochre pigment). These "chameleon" shades hold across multiple orientations.

In a south-facing room. Light amplifies warm shades and lets cool shades breathe. You have much more latitude.

To take advantage of the light: go with fresh shades that balance the warmth. Sage green, pale blue, pearl grey, cool off-white. The room will remain luminous but avoid the "oven" effect in summer.

To amplify the warmth (typical in Nordic countries where south-facing still means cold): terracotta, ochre, honey yellow, rich pink. Warm light multiplies these shades and creates almost Mediterranean interiors.

Farrow & Ball publishes an orientation recommendation for each shade in their range. Their Setting Plaster (warm powder pink) is explicitly recommended for north-facing rooms, because it maintains its warm tonality even under cool light. Conversely, their Cornforth White (slightly cool pearl grey) is advised against in north-facing rooms, where it becomes sad.

Pierre Yovanovitch often works "chameleon" shades in his multi-room projects. The same off-white can shift from warm to cool depending on the room, without changing the tin. He plays with light, not with the shade.

Studio KO conversely embraces the strong character of light depending on the country. In Morocco, their interiors amplify the warmth (intense ochres, terracotta) because the south light allows it. In France, they pull their palettes toward cool neutral (taupe, pearl grey) to respect the softer Atlantic light.