Most disappointing paint jobs are not badly applied. They are colours chosen under the wrong lamp. A north-facing Islington reception will cool a grey until it looks tired by November. The same grey on a south wall can feel almost stone.
We start with the window, not the fan deck. What time is the room used? Is the glass dirty with city film? Is there a tree? A colour that looks clay at noon can step back to brown once the sash is in shadow.
The practical method is dull and reliable. Paint two large samples, not postage stamps, on different walls. Look at them with the overhead light off. Look again after dusk with the lamp you actually own. If you only like it in the shop, it will not improve on your plaster.
True Coat leaves the samples up. We would rather lose a day than repaint a room that felt certain under retail lighting.
