Most architecture treats colour as the last decision. Mexico made it one of the first.

There's a print of a Barragán staircase on the wall by the roaster and every morning the light hits it at a different angle on the way down. Same image, different building, depending on the hour. 

We've stopped trying to catch it at its best. That shifting is the best of it.

You build the thing, then you choose what to paint it. That's the usual order, colour as the finish, the layer that goes on once the real decisions are made. Mexican modernism inverted it. 

Colour arrived early, as a structural idea, something the building was organised around rather than applied to. Ricardo Legorreta called it the culture of the wall and in his hands and Barragán's the wall was rarely white. It was a deep pink, a burnt orange, a blue that held its own against the sky. 

The surface carried as much of the design as the mass behind it.

The light is what makes it hold, or more precisely how much of it gets refused. Barragán was known for reducing daylight to a minimum, filtering it through yellow glass, pushing a window into the corner so the light came in sideways and low. A saturated wall in full midday sun flattens out and dies. The same wall in a shaded corridor, catching light that's been dimmed and angled, seems to hold colour in the air in front of it. Design the room dark enough and the colour has somewhere to go.

None of this began with one architect. The colour was inherited, pulled from the facades of San Miguel de Allende and Guanajuato, from colonial walls and village markets and from a landscape that never treated bright colour as a risk. Barragán took it from the street and the painter Chucho Reyes, who came out of Guadalajara as he did. Legorreta carried it forward and out into the world. Mathias Goeritz pushed it toward pure abstraction. 

It moved through hands and decades and stayed recognisable because the idea underneath it held. Colour was doing a job and every one of them built as if they knew it.

That's why these buildings have aged the way they have. A colour chosen as decoration dates the moment the trend moves. A colour built into how a room takes light has nowhere to fall out of fashion from. It's part of the structure. Move the sun and it simply becomes a different version of itself.

The print by the roaster will be a slightly different colour by the time we close. We've made our peace with that. Some walls are designed as function, these were designed to be lived beside and appreciated long after your second espresso of the day.

Shot of the good stuff.