We sell a huge range of matt emulsions. Dulux Trade and Crown Trade have an enormous number of colours on offer. Little Greene and Paint Library have slightly fewer colours but they are very well edited. These emulsions are all tinted on the spot to your order in a number of different can sizes from 250ml samples, 1L, 2.5L and 5L cans. As a rough rule of thumb a 2.5 Litre can will cover 20m² of wall with 2 coats.
Always "box" cans together - with the best will in the world cans vary between batches and the human eye is very sensitive to even the tiniest change so never run out of paint completely before buying more. Add some of your new can to the remains of your old one and you should get a perfect blend. Failing that, start a new can on a new wall - not in the middle - and you should not be able to tell the difference if there is a slight variation.