East-facing rooms get the best of the morning. The sun comes in low, warm and golden — gorgeous for a kitchen or breakfast room while you're having your coffee. The catch is what happens after about midday: the sun swings round to the other side of the house and the light turns cool, flat and a bit grey for the rest of the day.
That's the trap. People paint to the morning light, fall in love with how a colour glows at 8am, then wonder why the room feels dingy by teatime. So the rule for east-facing is: paint for the afternoon, not the morning. If it looks good in that cool, flat light, it'll look fantastic when the morning sun's on it.
Lean warm to balance the cool afternoons. Farrow & Ball Setting Plaster is a cracking east-facing choice — that soft pink-clay tone glows in the morning sun and stays warm and flattering once the light cools off. For something a touch more neutral, Pointing gives you a warm off-white that won't go cold and grey in the afternoon. If you want a bit of depth, Little Greene French Grey - Pale carries enough warmth to avoid the grey-flatness trap.
What about cooler colours — can you ever use a blue or a cool grey east-facing? You can, but go in with eyes open. The golden morning light takes the edge off them for a couple of hours, then the cool, flat afternoon doubles down and they sulk until bedtime. If that suits a bedroom you mainly use first thing, fine. For a living space you're in all evening, I'd steer you warm.
Practical bit: always check the sample on the wall that gets the *least* light, and look at it at three points — 8am, midday and 6pm. Two coats on big A2 boards you can move round the room, and never judge off the tin lid. Live with it a couple of days before you commit. East-facing light flatters everything first thing, so don't trust the morning impression.